Hey, little update.
It is just getting weirder.
Windows continues to have no issues at all with the audio.
I tried a manjaro xfce live usb today and a ubuntu lts live usb today, both only had the dummy output available. Now i boot back into manjaro, and my audio works again. I ran no commands whatsoever.
I can’t loose the feeling it might have to do something with grub, as my second linux sometimes when updating also updates grub and then changes the config. I believe this might have caused the issue in the first place.
Any ideas what to do now? I will leave my machine on standby for now in case there’s some sort of config to export here maybe…
Manjaro uses a hybrid GRUB and most other Linux distributions cannot update it correctly
other distributions are also likely to be using an older version of GRUB
If Manjaro GRUB is over-written it will need to be reinstalled
Manjaro created a script for this (install-grub) recently
Best option is to uninstall GRUB on other Linux OS. if that is not possible, install GRUB on other OS to a different location so it does not over-write Manjaro GRUB
Laptop/Lenovo - ArchWiki shows audio on Lenovo Thinkpad T14 is supported but requires sof-firmware driver (snd_sof_pci_intel_cnl) for the internal digital microphone
It seems like the issue is finally fixed!
I completely removed all grub stuff from the other OS with sudo apt remove grub-common, sudo apt remove grub-legacy and sudo apt remove grub-amd-64-somethingsomething.
I believe this issue is now finally solved, I will respond later if it persistently works or not.
Thanks a lot for all of the help!
edit: Nope, after three more reboots to manjaro it is broken again…