LTS upgrade to 22.04 stuck on snapd restart

[MR ZenWiz]

I have upgraded two of my machines from 20.04 to 22.04 with no real
problems. My third one is stuck waiting for the snapd to auto-restart
after starting to configure firefox.

I detest snap anyway, but the only way it seems to get rid of this is
reinstall the whole OS, which I would really rather not do.

I've tried using systemctl to restart the snapd, but that has no
effect. I can stop the service but it autorestarts just fine, and the
software upgrade GUI app does not seem to notice.

WTH?

Mark