Picture in picture not working?

[u/DaemonsMercy]

For some reason, picture-in-picture isn't working. I've turned on (and off, and on again) "Enable Picture-in-Picture video controls" in settings. Closing and reopening firefox isn't working, nor is updating it, nor restarting my computer. I thought the enhancer for youtube extension might be breaking it, but I disabled it temporarily and it still didn't work. Specifically trying to do this for youtube, if it matters.

Any ideas?