I use minimal debian templates for browsing and video conferences via zoom. Until the deb12 templates where moved to the stable repository I have used deb11 for those activities.
Since I have migrated to deb12 I have no sound when using zoom in its dedicated vm. The same is true for my deb12 browsing vm, however, only for brave and chromium since firefox works fine in the same vm, without any sound issues.
Using non minimal Debian 12 templates solved the issue.
I use dom0 as the audiovm for booth vms and have installed pulseaudio-qubes and qubes-audio-daemon in the vms templates for providing audio.