I find this in bugzilla:
https://bugzilla.redhat.com/show_bug.cgi?id=1983861
I think this is entirely normal in f35. The session manager >>is not started by pipewire anymore but by systemd.
You probably need to manually enable and start pipewire-media-session with:
systemctl --user enable pipewire-media-session systemctl --user start pipewire-media-session
I believe there is an update to the default policy on f35 >>scheduled. maybe it does not apply automatically for >>already installed components, I don't know.
Sound is working normally after starting pipewire-media-session