Are you running Ubuntu LTS? If so HWE or original kernel? I've only had one instance on my XPS where the HWE kernel broke something so I rolled back to the original kernel for a month or so.
I'm using popos that's based on 22.04, although it's at work so I can't check right now. I tried the steps here and also ones listed on stackexchange:
https://support.system76.com/articles/audio/
It's on pipewire. I only get a dummy audio device appearing. It does work when I use an external Bluetooth headset, and it actually did work previously -- I think there may have been a kernel update of some sort, and I tried to start up with an older kernel but no dice.
In general, pop os has been a pretty good experience, and I have used it on another work dell laptop (different job) and my Lenovo t480 since I stopped having the inclination to take care of Arch Linux (I might go back at some point, but I don't have much time to mess around anymore).
