So ditch the plugin altogether and install plex into a manually created jail. Here is a one command that should get it done. But please take care to edit the command to match your system or its not going to work. Specifically, change the IP address for the plex server (choose one in your subnet, but unique to your network), defaultrouter (its your gateway or router address). Please run this command from the Truenas host CLI, via ssh or open shell from the GUI.
echo '{"pkgs":["multimedia/plexmediaserver-plexpass","ca_root_nss"]}' > /tmp/pkgs.json && iocage create -r 13.2-RELEASE -p /tmp/pkgs.json -n plex ip4_addr="vnet0|192.168.0.222/24" defaultrouter=192.168.0.1 vnet=on boot=on allow_raw_sockets=1 host_hostname="PLEX" && iocage exec plex sysrc plexmediaserver_plexpass_enable=YES && iocage exec plex service plexmediaserver_plexpass start
Please let me know how it goes, i tested this and it does work if you edit the command correctly.
Then you would visit the chosen IP like so to configure.
