TV audio not going to the receiver when the Pi4 is plugged in.

I have a complex setup and an issue.

I have libreelec installed on a pi4. CEC is disabled for now. The HDMI0 port is connected to my LG C1 TV and the HDMI1 port to my Marantz SR7007. I did this so I can play HDR on my TV (the Marantz is not capable for that) and to have bitstreaming for all formats. This all works good.

Next I use squeezelite (addon package). I stop Kodi with node red and start squeezelite on HDMI1. This also works.

When everything is freshly started and working, I could go to watching TV on my TV, and the receiver switches to 'TV audio', and I

have sound.

So far so good. Now the issues:

When I turn of my TV, the Marantz does not turn off (which it should do).

When I switch the TV and receiver off, and I wait a few minutes, the following happens after that:

If I switch the TV on, the receiver turns on too. But I have no sound through the receiver anymore. When I try to change the volume on the TV, I get an icon saying it's not possible.

Only way to reset this, is to unplug both HDMI cables from the Pi, and turn off and then turn on the Marantz receiver. Then sound is coming back.

So I assume the receiver is getting 'locked' by the pi? Is there a way to 'unlock' this with software? Or maybe through the command line?

Already tried vcgencmd display_power 0 and vcgencmd display_power 1.

No one having an idea on how to solve this issue?

Quote from chewitt

https://wiki.libreelec.tv/configuration/edid#generic-x86_64 <= read up .. RPi4 under GBM/V4L2 is basically the same as any other Linux DRM device now, e.g. Intel.

So your saying I should create the edid files?

Quote from chewitt

It will either fix the issue or it won't .. so easy to test and try

I found my fix. I connected my receiver to my TV with an optical cable and use that for TV sound.