Can't play youtube videos in Big Sur
I can't play any youtube video in Safari after upgrading to Big Sur. The video just won't play. But I can preview the video if I place the pointer on the timeline.
And it happened once that I tried playing the video, it didn't start. Then I left it running and it entered the lock screen after a while. When I logged back in the video started playing.
What could have caused this problem?
Mac mini 2018 or later