CK1

So once again switched to Wayland and...: The settings are visible! All settings made according to amazingfate! Then downloaded a sample video (h.264 UHD + another sample in 1080p) and added it to the MOVIE library. -> For both videos neither picture nor tone! The progress bar is visible and the screen is gray. (Oh, I have now (re-)changed the power supply for an ANKER 30W, runs well)

I solved the booting problem by using a weak 5V 2A power supply! Then I installed everything according to your instructions. In KODI itself there are not the described options in the VIDEO Settings (Settings -> Player -> Videos, enable "Allow using DRM PRIME decoder" and "Allow hardware acceleration with DRM PRIME"). Also not around "Expert" mode. What am I missing here?

I have flashed your image to SD card using Etcher. The blue LED is blinking and it looks like the board is doing something. But there is no signal on the HDMI port, nor can I access the board via SSH. I have specially connected a strong power supply and did not use NVMe. What else could it be? I could boot a "standard" Debian 11 (CLI, without a desktop). What can this be?