Recently YouTube videos have stopped playing when I'm using the Firefox browser on Windows 10. This has occurred both on my laptop and on my desktop computer. The player, surrounding website, comments, description, etc. all load correctly. The video does not, instead displaying either the video's thumbnail and a buffering symbol, or a blank black screen and a buffering symbol. The time codes on the video load correctly. Ads do not play either, and instead after about 15-30 seconds of buffering the "skip ad" button appears in the lower right hand corner of the video. Videos play normally on both Chrome and Edge, and all other media content appears to load correctly (music/spotify, videos on social media websites, etc.) So far I have tried: - Running Firefox in troubleshoot mode - Refreshing Firefox - Clearing the cache - Disabling and re-enabling hardware acceleration (didn't work either way) - Uninstalling and reinstalling Firefox - Rebooting my machine - Waiting for the problem to fix itself (it's been two weeks on my main desktop/tower and it's still not working). At this point the only thing I haven't tried is messing with advanced config settings, and I'm avoiding that since I have no idea what any of them actually do (despite what certain reddit threads recommend). As far as I'm aware, no specific update to either of my machines or Firefox has preceded the issue appearing. It's been going on on my desktop computer for about two weeks, the problem just started on my laptop last night. It's worth nothing that I usually use UBlock Origin, Simple Tab Groups, and Facebook container. Those extensions are not currently installed since I had to reset my browser in the process of trying to fix the issue. I can also confirm it's not an internet issue; speed tests show normal download/upload speeds for my wifi, and those have not varied since the issue began. All of my drivers are also currently up to date.