Version 141.0.3 has severe stuttering when playing 4K videos on web pages. Previous versions and the Chrome browser both play them smoothly, so it's definitely not a hardware issue. I hope this can be fixed.
Experiencing 4K video stuttering in Firefox version 141.0.3 is a known issue, often linked to codec handling and hardware acceleration. To address this:
Install VP9 and AV1 Extensions: Ensure both "VP9 Video Extensions" and "AV1 Video Extension" are installed from the Microsoft Store.
Disable AV1 Codec: Navigate to about:config, search for media.av1.enabled, and set it to false.
Update Graphics Drivers: Outdated drivers can hinder video playback; ensure your GPU drivers are up to date.
Test in a New Profile: Create a fresh Firefox profile to rule out configuration issues.
