I recently bought a new iMac. I migrated my system from my MacBook to the iMac. In doing so it apparently migrated my Plex server's host name to my new machine. I've tried resetting it using Plex Media Server. I have a Samsung Smart TV with Plex installed. Both of my machines show up with the same server name in Plex on the Samsung.
In other words I have 2 machines, foobar.com (192.168.0.5) and baz.com (192.168.0.9). When I point my Plex app on the Samsung to either IP address I get the foobar.com hostname even though the IP address shows up as the last one I set it to. As a result the Smart TV Plex app will only allow one of the hosts to show in its host listing.
Where is Plex hiding the hostname for the server on OSx El Capitan? I'll be happy to delete the file. I'd delete Plex and reinstall it, but I know that lots of applications don't totally clean up after themselves.