I have been using Plex for years to manage a relatively large media library. I have two separate libraries, one for Movies and one for TV. For nearly three years, I have been running this with no problems on my Mac Mini (2011) and sourcing this out to both local devices and streaming off network.
About three months ago, I noticed that the Mac started failing consistently. After years of no up-time problems, the Mac would be turned off every time I went to watch something somewhere in the house. After completely wiping the machine and starting from scratch, the problems persisted. Thinking this was just my Mac finally giving up the ghost, I gave up and started fresh on my iMac (brand new i5 27" with 32 GB of ram). The first thing I noticed was that it is impossible for me to watch two libraries at the same time. To clarify: when setting up the server, I recreated my two libraries (TV and Movies) but noticed that only one would update at a time. After letting the movies data index over night, I came back the next morning and noticed that TV had not even began indexing, and I had to re-add the library to get it to index my TV shows.
Next, same as with my mac Mini, nearly every time I would come back to my iMac whenever PMS was running, it had shut down and needed to be restarted. I can leave my iMac on for weeks on end without it ever shutting down, but now its almost a guarantee that if I leave the machine running over night, it will be off by the next morning.
Finally, I then realized that Plex would not auto update any of my libraries when new media was added. Assuming there was something wrong with the installation of Plex, I started over, and completely uninstalled (including removing Library files from /Library and ~/Library), and then reinstalled.
Every single symptom remained.
I then realized that only about half of the roughly 900 movie titles had their meta data actually indexed, with no data or cover art in place. I went to refresh the library, and instead of fetching movie data, in simply removed all but one movie from the library, and I had to remove and re-add the library to get it to reload all my movies.
After finally getting it to scan all my libraries, the server is barely usable! I went to watch something on my TV, and it took three full minutes of attempting to load the file before it errored out. I'm yet to successfully watch anything from the server since moving it to my iMac.
Now, my iMac is brand new (less than 90 days old), with an i5, 32GB of ram, and a 1TB fusion drive. All the media lives on connected Thunderbolt devices which all appear to be functioning normally. I have hardwired CAT6 Connections between the iMac and a 16port Gigbait switch. Every device I have attempted to use Plex on (PS4, Xbox One S, Sony 4K Android TV) has also been hardwired to the same switch, all using CAT6 cables. Not that it matters for internal sourcing, but I have a 1Gbps fiber connection both up and down, and am having no issues with my internet, except for Plex.
What is going on???? How do I fix this? I'm willing to wipe my mac and start fresh, but given that many of these problems have existed across two machines, I'm not very excited about wiping and starting over, which would probably take me a day to get restored if I were truly starting from scratch and not a Time Machine restore.