Comment 8 for bug 1966436

Thanks for the support.

Indeed pipewire is part of the issue. Although installing kubuntu-desktop does not force pipewire (according to https://packages.ubuntu.com/jammy/kubuntu-desktop ), I may have enabled it wrongly while getting Wayland screensharing to work with the following:

sudo apt install xdg-desktop-portal-gnome gnome-remote-desktop # installs pipewire

systemctl --user enable pipewire-media-session
systemctl --user start pipewire-media-session
systemctl --user restart xdg-desktop-portal-gnome

This must have been what caused audio to break
(aside - I'd be happy to know the supported steps for xdg-portal sharing when upgrading to 22.04)

Thanks to your pointer I managed to fix it:
* recover the (wired) audio by installing wireplumber: this fixed half-setup pipewire situation.
* fix bluetooth by installing libspa-0.2-bluetooth (and restart bluetooth & wireplumber)
(see https://<email address hidden>/msg1826833.html)
So, closing this, and if it is considered an unsupported solution, sorry for taking your time!