You are 100% correct. This a new bug in Firefox. Probably introduced by something Youtube changed behind the scenes since they are constantly making changes to the video, audio & code on their website. [https://bugzil.la/1944207 Bug 1944207 - youtube.com - The audio keeps stuttering at a playback speed of more than 1x] * Play the video * Change the speed to more than 1x * Observe Expected Behavior: The audio is playing correctly Actual Behavior: The audio keeps stuttering and crackling If the description in that bug matches what you're seeing, I would join that bug report & make a comment saying you're seeing the same thing & would like steps on how to create a profile recording of the bug. Found these instructions from another bug on creating a log of a media playback bug: There may be clues in the logging, so if you're able to capture another profiler session when this issue is happening, that'd be appreciated. To capture the necessary logs, visit about:logging, select the "Media Playback" preset, then click "Set Log Modules" followed by "Start Logging" - this will start a new profiling session with the specified logs active. Then start the Youtube video and let the profiler/logging record for a minute or so. As long as the bug is happening during the recording, it should be a good log. I would also recommend you don't record for a bunch of minutes. As the log can become very huge in size. So maybe run the logging for 2 mins max then stop it. But I think 1 min is good enough. Next, upload the log/recording to https://profiler.firefox.com. I think you'll get a link for sharing afterwards. It should look like this example: [https://share.firefox.dev/4g86Tcz]. You can add that share link of your log to your Bugzilla comment & the developers can look at it.