Syphon-client do not capture game video under Big Sur

[BoeseBananeTV]

Hi there, I would like to capture gameplay (stream avatars) with syphon-client. Stream Avatars are still working under Big Sur now, but I can't select it with syphon-client. It also didn't works with syphoninject. I can select stream avatars, but there's always a black window. I allowed syphon to capture screen video on my mac-settings. Is there another workaround?