I also have been having this issue. I’ve tried using new claim tokens and resetting the Preferences.xml file.
[mod edit: your server’s certificate is perfectly fine. It appears your server doesn’t have remote access enabled at all. Do NOT use your own custom domain name to access your server in the local network. Verify you ar enot affected by Important note about the Plex Web app - Local Network Access
For all followup questions, please create your own forum thread.]
