Some Firefox users noticed playback issues on YouTube for several months. These affected high resolution videos only, from 1080p and up. To make matters worse, no clear pattern could be identified.
Some videos played fine, others would stop abruptly when they ran out of buffer.
Ya I’ve had this issue for months now, the video will freeze when the original 10 seconds of buffer is used, and it’ll play fine if I skip another 10 seconds but just buffer indefinitely otherwise.
You can get an extension to easily change your browser ‘user agent’ to make YouTube think you’re on chrome lol
Which one
Not OP, I use this https://addons.mozilla.org/en-US/firefox/addon/uaswitcher/
I’ve been having this exact issue too