The port-forwarding looks right, although I note mine is using protocol tcp_udp (coincidentally also rule 5 on mine)
rule 5 {
description Plex
forward-to {
address 192.168.1.5
port 32400
}
original-port 32400
protocol tcp_udp
}I assume you are trying to connect to the Plex server remotely, and not over the LAN?