All media server v.1.18.x updates cause server unreachable/unavailable after update

Just tried both local and hosted. Only difference is that hosted first complains about not being able to create a secure connection, so I select allow insecure once, and it goes to the same unreachable error anyway.
All web client access attempts pin the plex server process at 100% CPU.

Seems similar to symptoms in this thread Http://localhost:32400/web/index.html is unavailable but PLEX works on devices