Black/blank videos using sidecar ... ??

anyone know why I can't watch web videos on certain sites when I'm using iPad with sidecar as 2nd display? YouTube is fine but things like espn or some other sites like that (Ballys sports) I just get a blank/black screen for video. I can hEAR the audio for the video, but not see the video. as soon as I unplug the iPad and disconnect it from the Mac, the video appears as normal.