I didn't have issues on my main system (possibly due to reinstalling snaps before sync for testing) but my laptop decided to chuck a hissyfit today. Spotify snap would launch but no settings would save and launching from the command line showed a lot of errors.
WARNING: cgroup v2 is not fully supported yet, proceeding with partial confinement
update.go:85: cannot change mount namespace according to change mount (/var/lib/snapd/hostfs/tmp/.X11-unix /tmp/.X11-unix none bind,ro 0 0): cannot create directory "/tmp/.X11-unix": permission denied
/snap/spotify/46/bin/desktop-launch: line 276: /home/harvey/snap/spotify/46/.config/user-dirs.dirs: Permission denied
/snap/spotify/46/bin/desktop-launch: line 277: /home/harvey/snap/spotify/46/.config/user-dirs.dirs.md5sum: Permission denied
cp: cannot create regular file '/home/harvey/snap/spotify/46/.config/user-dirs.locale': Permission denied
/snap/spotify/46/bin/desktop-launch: line 282: /home/harvey/snap/spotify/46/.config/user-dirs.locale.md5sum: Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/themes': Permission denied
/snap/spotify/46/bin/desktop-launch: line 417: /home/harvey/snap/spotify/46/.config/fontconfig/fonts.conf: Permission denied
ln: failed to create symbolic link '/home/harvey/snap/spotify/46/.local/share/themes': Permission denied
ln: failed to create symbolic link '/home/harvey/snap/spotify/46/.themes': Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/mime/types': Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/mime/version': Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/mime/globs': Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/mime/magic': Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/mime/mime.cache': Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/mime/font/otf.xml': Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/mime/font/collection.xml': Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/mime/font/ttf.xml': Permission denied
rm: cannot remove '/home/harvey/snap/spotify/46/.local/share/mime/font/woff.xml': Permission denied
I'll spare you all the rest it goes on for like 600 lines. The solution was to reinstall the snap. Specifically I used --purge flag not sure if it matters
sudo snap remove --purge spotify
sudo snap install spotify
Spotify now works without issue with zero errors. So for anyone having issues with snaps, try purge the snap and then reinstall.