As the title says.
New ATV4, fully updated. Installed Plex App. successfully linked at plex.tv/link. Fully up to date server on local Mac Mini running Mac OS 10.11, and on the server status page it says "fully reachable from the internet" or similar verbiage.
I've restarted the Mini, the ATV, and my whole network.
Every time I go back into the Plex app on ATV, I have to go through the link process again, and then I get "Server offline."
Any ideas besides the ones at https://forums.plex.tv/discussion/230303/apple-tv-4-wont-load#latest which suggest taking my server back a version?