Boot the computer in Windows Safe Mode with network support to see if that has effect.

• https://www.bleepingcomputer.com/tuto.../how-to-start-windows-in-safe-mode/
• https://www.digitalcitizen.life/4-ways-boot-safe-mode-windows-10/

Set browser.privatebrowsing.forceMediaMemoryCache to true in about:config then restart the browser and see if it still happens when playing videos in a private window.

Unfortunately, my WiFi driver is deactivated in Safe Mode w/ Networking, so I am unable to test it that way.

Set browser.privatebrowsing.forceMediaMemoryCache to true in about:config then restart the browser and see if it still happens when playing videos in a private window.

I tried this tonight and Twitch stopped loading video after an hour. Surprisingly YT continued to load, but I don't think that helps narrow anything down.

I am currently trying it again with Firefox in Troubleshooting mode to see if any issues occur. If it still happens, I may trying going back to my fresh install backup of Windows 10 and see if it happens again.

I am still randomly encountering this problem, and it is random in both how it happens and what it affects. For example, today both Twitch and Reddit videos stopped working, but YT continues to work in both previews and playing. I've reinstalled video drivers a couple times, trying both what's on the Asus website and the newest Intel/Nvidia components. The only solution continues to be closing and reopening FF.

Capture a performance profile set to "Media" while the videos are stuck and share a link to it here.

Here's the profile of when it occurred today. Audio continued to play this time but the video was completely frozen and would not continue to load if I clicked on a different section of the video.

I've also updated to 121.0 to see if that would resolve it, but this recording was captured on the current version. Again the only way to resolve it was to restart the browser.

https://share.firefox.dev/3NSUIVK

Here's a capture from today: https://share.firefox.dev/3NSUIVK

This is from a YT video where all video froze but audio continued to play this time. If I tried going to a different timestamp, then audio would load again, but no video. This is on 121.0

It seems like you've taken comprehensive steps to troubleshoot the issue. Considering that the problem persists in Firefox but not in Edge, there could be browser-specific settings causing conflicts. In Firefox, try adjusting hardware acceleration settings. Navigate to Options > General > Performance and uncheck "Use hardware acceleration when available." This might alleviate video playback issues. Additionally, ensure your graphics drivers are up-to-date and compatible with Firefox. If the problem persists, reaching out to Firefox support or forums for more tailored assistance could be beneficial.