It works!

Im not sure it's supposed to have any effect on Desktop Firefox, but somehow it's fixed the issue I was facing - the url bar PiP button was constantly vanishing on youtube/displays despite the PiP right-click and floating button working fine

This extension seems to fix that perfectly as well!

awesome extension. the picture-in-picture works the same as the Google version but with more features, which is just what i was looking for.

Extension works so no longer have to deal with YouTube trying to break itself on Firefox instead of fixing their own app's memory leak issues.

I had no idea that YT intentionally broke PiP on android. It's been bugging me for years. This extension works perfectly, as far as I can tell. I've been running into a problem where the video stops loading and thus stops playing, and I have to reset the PiP window, but that may just be an Internet issue, and not the extension.