The additional issue for me running Home Assistant (not Core) is the SSH & Web terminal Add-on failed to start so it was impossible for me to access the HA CLI. The only thing I could do was power-cycle.
Now, lesson learned here is that when this error first occurred, the SSH addon was still working, but I did an HA restart as a normal first resort but this prevented SSH from restarting.
What I really need for insurance is an SSH daemon that runs independently and not dependent upon the Addons not starting due to other HA issues. So I would have to abandon Home Assistant and go the Core route to achieve that?