@leocg :|... in any case I have cases when it ends and this problem does not occur

When I watch YT videos and change tab I get the PIP working ok and I see a small window with the video in the corner. When I return to YT this small window disappears and I see the video in full size.

But sometimes this happens - the full sized video is black and the small window persists:

How to fix it so that always when I return to YT the window auto-closes and reopens when I change tabs?