New AVR - and some blank screen issues

Not sure. It’s possible that by default all the components are turned on (blue in the OSMC skin) and you have just turned off only the video component.

No, Video is blue and all the others are grey.

You are using HW decoding, right?

Yes, it’s on and all three options are set to Always.

Would debug logs help at all?

You could try but with verbose logging on, re-start kodi twice then play a video for no more than 10 seconds.

https://paste.osmc.tv/azitozuzan

Thx. I can’t see anyhing wrong there but will have a closer look later.