Video player in browser turns black when using sidecar

When I'm using my MacBook Pro 13"(M1 chip, Big Sur) and my iPad Pro as sidecar screen, some players (for instance the Udemy website player) in any browser I have installed turn black while playing, although the audio works fine and all the controls are working fine. As soon as I disconnect from sidecar I can play the video with no issues. I've tried to google this issue, but no luck. Any idea?