Is this still the situation?:
- https://app.plex.tv/desktop/#!/ works
- https://192.168.0.30:32400/web does not work
What has changed since your December post, when local access worked?
Remove 192.168.0.1/24 from Settings → Network → LAN Networks if it is still there.
Please supply a set of server log files. They are needed to determine what is happening.
