Are you sure you are running the beta version of 3.20 btw ? :)

Anyway, I did the CMI8738 AHI driver around 2017 when the X5000 started to show up and it didn't change much since then...

You could try to edit the env variable envarc:cmi8738.audio, put the string

Code:

into it, reboot and check if it makes any difference.