Firefox Community Forum

Hi,

two days ago, video embeds on Twitter stopped working in Firefox. Please help me troubleshoot the issue, so that I can either fix it myself, or present enough evidence to file a proper bug report.

Affected version: FF 140 ESR. I had some 140.7 installed when the error first happened, but have upgraded to firefox-esr_140.10.1esr-1_amd64 since. Didn't fix the problem. *Not* a snap package, regular .deb!

Affected OS: Ubuntu 26.04 LTS, not a fresh install but upgraded from 24.04 instead (which itself was upgraded from 22.04).

Symptoms: Videos on X (and Facebook) no longer play, the preview image is there for a split second, then an error appears. Video on for example Youtube is fine, though. Local players like VLC also do work as expected. Video on X worked under 26.04 before this happened.

The issue likely started when removing surplus packages and metapackages from the upgrade. According to synaptics, this is the complete list of packages removed: augeas-lenses bomber bovo clevis clevis-luks db-util db5.3-util dolphin-dev gir1.2-freedesktop-dev gir1.2-glib-2.0-dev girepository-tools gostsum granatier guestfish guestfs-tools guestmount icu-devtools jose kapman katomic kblackbox kblocks kbounce kbreakout kdegames kdegames-mahjongg-data-kf6 kdiamond kfourinline kgeography kgeography-data kgoldrunner kigo killbots kiriki kjumpingcube klickety klines kmahjongg knavalbattle knetwalk knights kolf kollision konquest kreversi kshisen ksirk ksnakeduel kspaceduel ksquares ktuberling ktuberling-data kubrick kubuntu-web-shortcuts ldmtool libaom-dev libarchive-tools libaugeas0 libblkid-dev libconfig11 libdbus-1-dev libdlt3 libffi-dev libfmt-dev libfontconfig1-dev libfribidi-dev libgd-perl libgio-2.0-dev libgio-2.0-dev-bin libglib2.0-dev libglib2.0-dev-bin libgraphite2-dev libguestfs-perl libguestfs-tools libguestfs0t64 libharfbuzz-cairo0 libharfbuzz-dev libhivex0 libicu-dev libjose0 libjson-glib-dev libjxr-tools libjxr0t64 libkdegames6private6 libkmahjongg6 libldm-1.0-0t64 libmosquitto1 libmount-dev libosinfo-1.0-0 libosinfo-l10n libpcre2-dev libpixman-1-dev libpolkit-gobject-1-dev libpsl-dev libpwquality-tools libpython3-dev libpython3.14-dev libselinux-dev libsepol-dev libspdlog-dev libsqlite3-dev libssh-dev libstd-rust-dev libstring-shellquote-perl libsys-virt-perl libsysprof-capture-4-dev libsystemd-dev libtirpc-dev libusb-0.1-4 libusb-1.0-0-dev libusb-1.0-doc libusb-dev libvirt-common libvirt0 libwebsockets19t64 libwhoopsie-preferences0 libwhoopsie0 libwin-hivex-perl libx265-dev libxdo-dev libxdo3 libxft-dev libxkbcommon-dev libxrender-dev libyara10 lskat lskat-data mosquitto mosquitto-clients native-architecture osinfo-db palapeli palapeli-data picmi qml6-module-org-kde-games-core skladnik supermin whoopsie whoopsie-preferences I don't think they are related (libx265 and libaom are only the -dev packages), but this is the only system-wide change on that day that I can remember. I of course tried re-installing these, but this also doesn't fix the problem.

On my journey of fixing this myself, I also asked the all-hallucinating knowledge randomizer frontend of OpenAI, which made me check a couple generic spots on my system and in FF itself.

ffmpeg -codecs | grep -E "h264|hevc|vp9|av1" ffmpeg version 8.0.1-3ubuntu2 Copyright (c) 2000-2025 the FFmpeg developers

 built with gcc 15 (Ubuntu 15.2.0-13ubuntu3)
 configuration: --prefix=/usr --extra-version=3ubuntu2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --disable-pocketsphinx --disable-libcaca --disable-libmfx --disable-omx --enable-gnutls --enable-libaom --enable-libass --enable-libbs2b --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libharfbuzz --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-openal --enable-opencl --enable-opengl --disable-sndio --enable-libvpl --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-ladspa --enable-libbluray --enable-libdvdnav --enable-libdvdread --enable-libjack --enable-libjxl --enable-libpulse --enable-librabbitmq --enable-librist --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libx264 --enable-libzmq --enable-libzvbi --enable-lv2 --enable-sdl2 --enable-libplacebo --enable-librav1e --enable-librsvg --enable-shared
 WARNING: library configuration mismatch
 avcodec     configuration: --prefix=/usr --extra-version=3ubuntu2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --disable-pocketsphinx --disable-libcaca --disable-libmfx --disable-omx --enable-gnutls --enable-libaom --enable-libass --enable-libbs2b --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libharfbuzz --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-openal --enable-opencl --enable-opengl --disable-sndio --enable-libvpl --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-ladspa --enable-libbluray --enable-libdvdnav --enable-libdvdread --enable-libjack --enable-libjxl --enable-libpulse --enable-librabbitmq --enable-librist --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libx264 --enable-libzmq --enable-libzvbi --enable-lv2 --enable-sdl2 --enable-libplacebo --enable-librav1e --enable-librsvg --enable-shared --enable-version3 --disable-doc --disable-programs --disable-static --enable-libaribb24 --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libtesseract --enable-libvo_amrwbenc --enable-libsmbclient
 libavutil      60.  8.100 / 60.  8.100
 libavcodec     62. 11.100 / 62. 11.100
 libavformat    62.  3.100 / 62.  3.100
 libavdevice    62.  1.100 / 62.  1.100
 libavfilter    11.  4.100 / 11.  4.100
 libswscale      9.  1.100 /  9.  1.100
 libswresample   6.  1.100 /  6.  1.100
DEV.L. av1                  Alliance for Open Media AV1 (decoders: libdav1d libaom-av1 av1 av1_cuvid av1_qsv) (encoders: libaom-av1 librav1e libsvtav1 av1_nvenc av1_qsv av1_vaapi av1_vulkan)
DEV.LS h264                 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (decoders: h264 h264_v4l2m2m h264_qsv h264_cuvid) (encoders: libx264 libx264rgb h264_nvenc h264_qsv h264_v4l2m2m h264_vaapi h264_vulkan)
DEV.L. hevc                 H.265 / HEVC (High Efficiency Video Coding) (decoders: hevc hevc_qsv hevc_v4l2m2m hevc_cuvid) (encoders: libx265 hevc_nvenc hevc_qsv hevc_v4l2m2m hevc_vaapi hevc_vulkan)
DEV.L. vp9                  Google VP9 (decoders: vp9 vp9_v4l2m2m libvpx-vp9 vp9_cuvid vp9_qsv) (encoders: libvpx-vp9 vp9_vaapi vp9_qsv)
DEAIL. wmav1                Windows Media Audio 1

-> ffmpeg is installed, version 8, av1 and hevc support seems present. The sparse advice from google results (similar thing in a Gentoo forum I think) on installating ffmpeg4.4 is no longer viable. --- apt list --installed | grep libavcodec

libavcodec-dev/resolute,now 7:8.0.1-3ubuntu2 amd64 [installed] libavcodec-extra62/resolute,now 7:8.0.1-3ubuntu2 amd64 [installed,automatic] libavcodec-extra/resolute,now 7:8.0.1-3ubuntu2 amd64 [installed]

(libavcodec62 non-extra was installed before, didn't change anything) --- apt list --installed | grep libaom*

libao-common/resolute,resolute,now 1.2.2+20180113-1.2ubuntu2 all [installed,automatic] libao4/resolute,now 1.2.2+20180113-1.2ubuntu2 amd64 [installed,automatic] libaom3/resolute,now 3.13.1-2 amd64 [installed,automatic] --- FF about:support in the codec section says this: Codec Support Information Codec Name Software Decoding Hardware Decoding H264 Unsupported Supported VP9 Supported Supported VP8 Supported Supported AV1 Supported Unsupported HEVC Unsupported Supported AAC Unsupported Unsupported MP3 Supported Unsupported Opus Supported Unsupported Vorbis Supported Unsupported FLAC Supported Unsupported Wave Supported Unsupported --- vainfo Trying display: wayland libva info: VA-API version 1.23.0 libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so libva info: Found init function __vaDriverInit_1_22 libva info: va_openDriver() returns 0 vainfo: VA-API version: 1.23 (libva 2.22.0) vainfo: Driver version: Intel iHD driver for Intel(R) Gen Graphics - 26.1.2 () vainfo: Supported profile and entrypoints

     VAProfileMPEG2Simple            : VAEntrypointVLD
     VAProfileMPEG2Main              : VAEntrypointVLD
     VAProfileH264Main               : VAEntrypointVLD
     VAProfileH264Main               : VAEntrypointEncSliceLP
     VAProfileH264High               : VAEntrypointVLD
     VAProfileH264High               : VAEntrypointEncSliceLP
     VAProfileJPEGBaseline           : VAEntrypointVLD
     VAProfileJPEGBaseline           : VAEntrypointEncPicture
     VAProfileH264ConstrainedBaseline: VAEntrypointVLD
     VAProfileH264ConstrainedBaseline: VAEntrypointEncSliceLP
     VAProfileVP8Version0_3          : VAEntrypointVLD
     VAProfileHEVCMain               : VAEntrypointVLD
     VAProfileHEVCMain10             : VAEntrypointVLD
     VAProfileVP9Profile0            : VAEntrypointVLD
     VAProfileVP9Profile2            : VAEntrypointVLD

--- running with MOZ_DISABLE_HW_DECODE=1 firefox -> no change --- A fresh profile shows the same issues, so this should not be config-related in terms of Firefox --- Safe mode on my standard profile also doesn't change anything --- running with MOZ_LOG="PlatformDecoderModule:5" firefox -> also no change, but now on every try to play a video, these three lines are spammed: [Child 2326924: Main Thread]: D/PlatformDecoderModule Sandbox Utility Generic decoder rejects requested type video/avc [Child 2326924: Main Thread]: D/PlatformDecoderModule Sandbox Utility Generic decoder rejects requested type video/av1 [Child 2326924: Main Thread]: D/PlatformDecoderModule Sandbox Utility Generic decoder rejects requested type video/hevc

On other websites, the occasional [Child 2330726: Main Thread]: D/PlatformDecoderModule Sandbox Utility Generic decoder rejects requested type audio/mp4a-latm or [Child 2331802: Main Thread]: D/PlatformDecoderModule Sandbox Utility Generic decoder rejects requested type video/vp8

is added.

Some time close to starting FF, this block is presented: [Utility 2331783: Main Thread]: D/PlatformDecoderModule PDMInitializer, Init PDMs in Utility process [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFMPEG: version: 0x200, macro: 62, micro: 101, isFFMpeg: yes [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFVPX: Link result: Success [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder rejects requested type 'video/avc' [Utility 2331783: Main Thread]: D/PlatformDecoderModule Agnostic decoder rejects requested type 'video/avc' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'video/vp9' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'video/vp9' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'video/vp8' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'video/vp8' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'video/av1' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'video/av1' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder rejects requested type 'video/hevc' [Utility 2331783: Main Thread]: D/PlatformDecoderModule Agnostic decoder rejects requested type 'video/hevc' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder rejects requested type 'audio/mp4a-latm' [Utility 2331783: Main Thread]: D/PlatformDecoderModule Agnostic decoder rejects requested type 'audio/mp4a-latm' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/mpeg' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/mpeg' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/opus' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/opus' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/vorbis' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/vorbis' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/flac' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/flac' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/x-wav' [Utility 2331783: Main Thread]: D/PlatformDecoderModule FFmpeg decoder supports requested type 'audio/x-wav' [Parent 2331581: Main Thread]: D/PlatformDecoderModule Broadcast support from 'Utility Generic', support=H264 NONE VP9 SW VP8 SW AV1 SW HEVC NONE AAC NONE MP3 SW Opus SW Vorbis SW FLAC SW Wave SW

Back in FF 140.7, I also got these lines, but they're no longer present in 140.10 or flags have changed, I don't know: [Child 2238921, MediaDecoderStateMachine #1] WARNING: Decoder=7329b02ba900 state=DECODING_METADATA Decode metadata failed, shutting down decoder: file ./dom/media/MediaDecoderStateMachine.cpp:371 [Child 2238921, MediaDecoderStateMachine #1] WARNING: Decoder=7329b02ba900 Decode error: NS_ERROR_DOM_MEDIA_METADATA_ERR (0x806e0006): file ./dom/media/MediaDecoderStateMachineBase.cpp:168

--- The troubleshooting info below this text box says this somewhere:

"name": "AV1_HW_DECODE",
         "description": "AV1 hardware decoding",
         "status": "blocklisted",
         "log": [
           {
             "type": "default",
             "status": "available"
           },
           {
             "type": "env",
             "status": "blocklisted",
             "failureId": "FEATURE_FAILURE_VIDEO_DECODING_MISSING",
             "message": "#BLOCKLIST_FEATURE_FAILURE_VIDEO_DECODING_MISSING"
           }

Open to suggestions on where to dig deeper next...thank you!

Yesterday I updated Firefox to version 115.22.0esr this morning when it was released. Have never had any problems viewing video on Netflix but now I am getting Netflix error message F7702-1003. Yesterday I asked "what can I do? I've rebooted computer as Netflix says and it didn't help."

Today, to see if the issue was a bug with version 115.22.0 esr I logged onto both Peacock and Hoopla to try to stream video. On both sites the same thing happened that happened on Netflix. I log into the site, select a video, and when I try to play it I get a message that "widevineCdm plugin has crashed" and video won't play.

Since this problem just appeared after I updated to version 115.22.0 esr it seems likely that there is a bug in this version which is crashing the plugin and preventing streaming video. I note that I can stream some video having checked both YouTube and an online television station.

Hello Firefox Support,

I’m encountering a strange issue with Firefox. While playing YouTube videos at very low quality (144p) just to listen to music, my GPU usage spikes to 100%. This happens even when the video is not fullscreen and there’s minimal visual content.

System Info:

   Firefox Version: 140.0.2 (64-bit)

   Operating System: Windows 11 

   CPU: AMD Ryzen 7 8700F (no integrated GPU)

   GPU: AMD Radeon RX 7900 GRE

   GPU Driver Version: AMD Adrenalin 25.6.1 

The issue goes away when I disable hardware acceleration in Firefox settings, but I’d prefer to leave it enabled for better performance elsewhere.

Is this a known issue with AMD GPUs or is there something else I can try to reduce GPU usage during playback?

Thank you for your help.

Trouble with streaming services(like youtube(only streams ), twitch, music streaming) on nightly Firefox Nightly 145.0a1 (2025-10-11) (x64) Cachy OS Binary from firefox.com

Using iOS on Mac Mini desktop, I get no sound on democracynow.org but on the iPhone the sound works fine. Most other streams/videos have fine sound but not imdb.com on the desktop with iOS but again, fine on the iPhone.

I've been searching for an answer to this for weeks to no avail. It concerns YouTube videos "autoplay"ing on YouTube. Many have asked this question and most responses state to shut off Autoplay. These are two separate issues. AotuPlay means the next video on YouTube will advnace automatically requiring no user input. If Autoplay is off, streaming stops at the end of the video. The issue I am having is when I open a YouTube video to a new tab (but do not switch to that tab), the video WILL start playing as soon as that tab is in focus. This never used to happen and indeed, on two other computers with the settings and extensions all sync'ed, this doesn't happen, except for on this one computer. Today I found someone that posted the exact same problem 5 years ago and didn't get an answer. He seems to describe it well:

1. Okay, so before, when I loaded up 100+ Youtube videos, they stayed when switching tabs - no autoplay. Suddenly they decide to autoplay when switching tabs - note, I've not done anything to my settings or plugins. Fair enough, maybe you changed something (which you often do, without informing). So I check the options. It was on "Block audio", which obviously didn't work, so I tried "Block Audio and Video" - which WORKS, but now both the video is paused (which I want) AND the audio is set to mute (which I DON'T want) - so... what does it take to have Youtube wait for a click to start playing a video loaded in a background tab, but KEEP AUDIO ACTIVE, so I don't also have to unmute the damn video?

One person posted a possible solution: Maybe check this pref on the about:config page.

   media.block-autoplay-until-in-foreground 

This setting describes the issue kind of. If you have this set to false, the moment you send a link to a new tab, YouTube starts playing in the background. Setting it to false keeps the video paused until that tab is in focus. That is how mine has always been set. What I am looking for is a setting that would say something like: "block autoplay until play is pressed"

Thanks in advance and sorry for being so long-winded

When I listen to music via Firefox, my computer goes into sleep mode after 15 minutes (windows close and password is required)^)^. I've looked everywhere to find a solution to this problem, but I can't find one... Can you help me?

Hello,

I am having an issue with my Bluetooth headphones (Sennheiser HD 450BT) in Firefox on Windows 11.

The headphones are properly connected to Windows and work correctly with other browsers (Edge, Chrome).

Windows shows the headphones as the default output device (stereo), and test sounds play through them.

However, in Firefox, the audio does not go through the headphones. Instead, it plays very loudly through the laptop speakers.

The problem started today; there were no issues for about a year.

I have tried reconnecting/reinstalling the headphones, but it did not help. Drivers are also up to date.

Could you please advise how to make Firefox correctly use my Bluetooth headphones as the audio output device?

Thank you for your assistance.

Trying to run Prime and Netflix in a Linux browser on my new Lenovo Chromebook Plus 14. Not that this is an ARM based unit (Kompanio Ultra 910).

I can successfully download Firefox for Linux: Mozilla Firefox Debian Package mozilla-deb-1.0 144.0 (aarch64)

But when I go to run streaming video services get: Prime Video is incompatible with your current operating system or web browser. You must update to watch Prime Video titles. Review the Prime Video system requirements. If the problem continues, please contact Amazon Customer Service and refer to error 7132.

Same with Netflix.

any ideas, thoughts, solutions?  :)

Cheers.

My Firefox browser has been crashing for a while now (Years). It's fine playing YouTube and BBC iPlayer but when I advance the time marker to a different part of the stream or video, it crashes. It also has a problem when playing slots. It seems to crash a lot making it impossible to play.

I have tried using Firefox in Troubleshooting Mode but the same things happen.

Here's the crash report ID

Report ID Date Submitted bp-a9b8bd6e-9258-4a25-badc-bda480250308 08/03/2025, 13:41

Many thanks in anticipation and I hope someone can help me fix these issues.

Whenever I play something in the browser while connected to my TV by HDMI, the sound still comes out of the laptop speakers. This happened suddenly, without any discernible reason, and I can't seem to fix it. Everything else works, only content played from Firefox remains in the laptop speakers. I've checked my audio mixer, nothing seems amiss, I've updated Firefox and refreshed the application, still nothing. Hell, I've even tried different cables and HDMI ports, but nothing works. What could be the issue? Why did my audio suddenly stop working, and what can I do about it?

Lost my audio on Firefox. All movies and web site videos SILENT

Strange exceptions: e.g., can't ear video on youtube.com; BUT, CAN hear it if web page has LINK to YouTube!?!? SOME Twitter videous have audio; others are silent

How do I turn Firefox audio back ON?

I've noticed that whenever I press ⌥⇧Space (option-shift-spacebar) in Firefox Developer Edition, it causes the page to refresh.

This behaviour seems to be consistent across devices.

Is there a way to change/disable this behaviour? It is very inconvenient, as it often causes me to accidentally trigger a page refresh when I type an em dash (`—`) in a text input (opt-shift-dash, and then type a space character after it, I'm very likely to hit opt-shift-space by mistake 🙈).

Reposting until I get help from someone. Windows/desktop. On Google Chrome, any streaming website I used with autoplay enabled would KEEP full screen mode ON after changing episodes. It would automatically go to a new page with the following episode and remain full screen. Why doesn't Firefox have this feature?? I'm seriously considering going back to Google Chrome for this one small feature. Every time I had any streaming service playing with autoplay enabled, I didn't have to manually select the full screen option every time. I am having to stand up and manually click full screen function. Every. Single. Time. Somebody please help me if there's a way to active that function.

When I navigate to youtube and try to watch a video, the player does not load. It just shows white in the space where the player should be. No video, no audio, no nothing. No matter what video I click, the same thing happens. The only workaround I have found is that if I go to a page with an embedded youtube video, and click the "watch on youtube" link that appears in it, it will load a youtube page that can play videos normally. I can use that page to navigate youtube and it will operate normally. However if I type in youtube.com or get to the site some other way, the issue happens where it is only white space. It is very frustrating.

This is a functional bug, not a settings issue. Block media autoplay in Firefox cannot work, after I right-click on a blank area of the page and scroll.

For example, I saw a post with a video on x.com, and the site was set to prohibit automatic video playback. But when I right-clicked on the webpage and then scrolled the page with the mouse, the video started to play automatically, which means that the function of prohibiting video playback was invalid. Very strange.

Firefox version: 141.0.3 (private-browsing No extensions are running) OS: Windows11 Enterprise 26100.4946