macOS Now Playing and Screen time doesn't work properly with Safari

I've been having this bug for years, on multiple macOS versions, and on multiple macs.

Basically, if I open a page that plays video on Safari, like YouTube, or Twitter/X, most of the time, that content will still be shown in the "Now Playing" system menu, even long after I closed the tab.

Incidentally, screen time also consistently records 24 hours of youtube a day, unless I kill the Safari process entirely.

Through trial and error, I found out that if I kill the 'com.apple.WebKit.GPU' process, safari goes away from the now playing menu.

My guess is that this is some bug related to DRM? Not sure, anyway, it is **really** annoying - would be nice to have a fix for it.