NAT - Portforwarding - same port working, different not

[HolgerKuehn]

Hi folks,

I've been trying to figure out why one of my portforwardings seems not to be working.

I'm using a PlexMediaServer on my NAS, it's requiring port 32400 for remote access. If I configure the same port on WAN, it's stable. But when using port 80 on the WAN for it, it stops working. I used to do this before I switched to OPNsense, as most guest networks only allow traffic on ports 80 and 443.

Is there any (standard) configuration that might use the port 80 already, so that it's not working here?

The attachments show the aliases and NAT rules I've configured. I'll limit the source to specific known networks later, but like to understand why it's not working in this simple setup.

Holger

[HolgerKuehn]

Have done some more testing, it's only port 80 that's not working here. And found some other thread, and changed the GUI-ports to only 443 and LAN, but it still persists.

Anything I missed?