Discovery/Hubs endpoint returns non-JSON, even though you get HTTP 200. There’s a repeating patter of, Completed request …/hubs/sections/2… with code 200
immediately followed by Error parsing JSON … JSON Parse error: Unexpected character: i then Discovery: Error retrieving data for hubs.” “Discovery: … offline: true.
Do you have some middleware/reverse proxy in front of plex? Are apps and server both up to date?
Your phone can’t reach the server’s LAN address, so it falls back to remote. There are repeated failures to local endpoints: https://192-168-1-217...plex.direct:32400 -> -28 (timeout) but plex.direct host works: https://176-228-173-197...plex.direct:32400 -> 200
Your phone and server are on different subnets, phone is 10.100.102.212 and server is 192.168.1.217, this isn’t a problem if setup properly.
I would sign out of plexamp and delete the app, then re-install and sign in again to fix any corrupted local save state. Double check your internal LAN config and simplify it for troubleshooting purposes then start adding layers back to determine cause.