Greasy Fork is available in English.
Prevents YouTube and Vimeo from pausing videos when minimizing or switching tabs. Cross-browser port of https://addons.mozilla.org/en-US/firefox/addon/video-background-play-fix/
< Обсуждения Video Background Play Fix
This is the problem
So the problem here is that the latest version started trying to inject the visibility properties to document.wrappedJSObject, which doesn't exist in chromium. Changing document.wrappedJSObject to simply document makes it work again. Alternatively, go back to the previous version and disable auto-updates to it. Pinging @Couchy so he can see.
Doesn't work for Kiwi browser