ASUS RoG Strix Z790-F: SPDIF (PCM) has wrong channels | how to get passthrough working?

[Nightwing0815]

Hi there,

finally, after a long journey, yesterday I did an update from linuxmint to newest version 22, based on ubuntu 24.04 (I'll attach alsa-info and a system info).

Now it's no big problem any more, to get SPDIF working: I just selected the right device and muted all others in alsamixer, except the pcm signal.
But hey, there's a new problem:
With a speaker-test -c6, I'm not able to hear my rear channels and the lfe channel, where they should be. Rear coming on front speakers...
So, what do I have to do?
Further, I'm asking for help to configure a pcm signal passthru for dts and (e)ac3 soundfiles. My teufel receiver recognices only a 5.1 stereo source, not an DD5.1 or DTS signal...

alsa-info.txt
sysinfo.txt

Thanks in advance for getting this problems solved,

ToM