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....
"This problem is triggered by bad muxed VP9 bytestream served by Youtube, so it's not a regression on our side, this issue can also be reproduced on old versions Firefox".
Google disrupted YouTube video playback on Firefox, again - gHacks Tech News (ghacks.net) en
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....