I have a plex server that I used to have access to that is no longer online. It is in my list of servers and I cannot delete it. I have went to Settings->Authorized Devices->Servers and it is not listed there. My client keeps trying to reconnect to it and I need to remove it. Any suggestions are welcome.
Are you talking about a shared server (i.e. not your own)?
If so, you can “leave” the server in your Friends list. https://app.plex.tv/desktop/#!/settings/manage-library-access
Click on the name of the server owner.
Then “Edit” on the defunct server.