Issues with CEC and weird colors when playing HDR 4k content (RPi4, Samsung S95B, NAD)

Hi,

I recently switched to 4k HDR playback with my RPi4. After some initial issues with choppy playback everything works nicely except for two things.

After coming back with the TV of I have trouble with CEC not being active. I have to press an old IR remote in order to wake Kodi up. After that I can use the TV remote. When looking at the source (AVR, NAD) on the TV when this issue occur, there is no Anynet+ menu until I wake Kodi in some other way.

Are there any recommendations on how to configure the CEC plugin in Kodi to match my Samsung (S95B) for better compatibility?

Another issue which is even more annoying, but not as frequent is that when coming back all HDR 4k content has crazy colors, a lot of green and pink, SD/HD content are fine. Rebooting TV, AVR or Kodi separately wont solve the problem, instead I have to shut everything down and then start it up again to get the proper colors back.

Is this known and do you have any suggestions how to solve this issue?

I do not really understand what you mean. Do you suggest I should add another cable to my RPi and connect separately to the TV? Can I keep the ARC since its needed for other sources?

The RPi is currently only connected to the AVR since it has no support for eARC and hence is limited in what sound it can pass trough.