It could be, I almost never actually use my dock so hard to judge. with it being intermittent over usbc and not being affected by different cables I would hazard a guess that either the dock is having issues, or steamOS is though. If you’re ok with using the konsole you could try

cat /var/log/syslog* | grep -i pulse

and see if it states what’s going on with the audio server.

Edit: journalctl would also work if you want to see logs in real time while debugging, use

sudo journalctl -f