I recently upgraded from CORE to SCALE 24.10 and my Plex performance went kablooie: All sorts of “non-local network” messages, especially for Plex managed-users; couldn’t get subtitles to work at all; and the Plex apps (running on SHIELDs) often needed several attempts just to see the contents of my libraries. All of this was smooth as butter under CORE on the same hardware.
After pulling my hair out a few times, I finally enabled the Host Network option in the TrueNAS config for the Plex app.
That fixed everything! Plex is once again rocking, just like it did in CORE.
The effect of this setting is that the Plex server’s container uses the TrueNAS host’s IP address, instead of something from the internal Kubernetes/Docker 172.16.0.0/12 subnet. (You can see what address your Plex server is actually using on the Plex Remote Access settings page.)
I’ve seen other advice saying that enabling the Host Network setting has security implications. This is true, and you should understand how your NAS is exposed to your network before enabling this.
In my case, my NAS is completely inside my private network, behind a firewall that does port-forwarding. I see no downside to letting the Plex server use the NAS’s IP address. If you’re worried about this, you should investigate methods for letting TrueNAS docker containers have their own IP addresses (e.g. the Dockge app, which I’ve never used).
I must say that this setting is pretty much required for Plex! You really really want your Plex server to be in the same subnet as your player apps. It would be nice if the app’s installer enabled this. Without it, I think all of my videos were going through Plex’s streaming proxies on the Internet…