Since the latest Tumbleweed update, pipewire got updated to version 0.3.23
symptom:
No ALSA sound card is seen nor used by piprewire.
reason:
Since version 0.3.23, the media sessions is started separately from pipewire.
And not directly by the main pipewire service based on the various session files in its configuration directory.
solution:
Enable the media serssion:
systemctl --user enable --now pipewire-media-session.service