Not VPN, but Browser (Couldn’t find a sub for browser sorry)
Went away for a week on holiday, returned and updated Mullvad browser, went to chill on YouTube and every video has these lines at the bottom half of the frame. I thought maybe dying GPU but in gaming theres no issues whatsoever. Twitch livestreams seem to function fine as well. Chrome browser (yes you can hate me for still having it installed) doesn’t have this issue.
Getting these too since the last update. Thought my graphics card was dying for a second.
Same, I think I found when maximized it went away
I feel like this is something to do with the anti-fingerprinting.
This is because youtube is using the canvas API for displaying a transparent image.
The Canvas API is partially blocked to prevent browser fingerprinting, so these artifacts appear.
I also thought my graphics card was fried, thankfully someone posted this here 
Yea it seems related to the playback buttons on the bottom (play, sound, duration bar etc), when those display i.e when hovered over playback, those lines display, after a few seconds they’ll disappear alongside the playback buttons. My guess is YouTube have changed something…
Aah, is there a workaround atm? Seemed to only become an issue after recent mullvad update.
My thoughts as well haha. Unsure when the update released but I def wasn’t the first user of it, but to see nobody else posting, had me concerned too haha.
You can use uBO to block the image itself.
Here’s what you can add to the custom rule:
