[Ugoos AM6B+] No video when playing media

Hello, I am experiencing an issue with video playback.
I have the ugoos am6b+ connected to my AVR (yamaha rxa660) which in turn is connected to my TV. When not playing media, video works fine. I configured the recommended settings following the guides available on the forum. When I start a video I can see on the AVR display it is switching. The audio does work. But video does not.

When I plug the device directly into the TV it does output video correctly but audio and the tv remote dont work any more. This might be because I plugged into an arc port, but nevertheless I want it to work via the AVR. I have checked the hdmi cables, all are high speed hdmi cables. I tried several different audio settings, I configured passthrough correctly using the formats available on the AVR. I looked into the debug log to see if there are any errors/warnings but there were only info/debug messages, nothing indicating an issue.

What can I try next?