Here's the list of required ports:
And here's the Port Forward screen in the GUI (router is R7800, latest KONG build):
The game is still NAT Type MODERATE and it causes strange issues when playing co-op with friends.
Anything wrong in the setup above?
You appear to have opened ports to the router itself, rather than forwarding. But it is hard to see on a screenshot.
Please post your /etc/config/firewall file - easiest for us to review that.
Actually you might have the port forwarding configured appropriately, but you have not opened the ports exactly as specified in the game support info you provided.
The port forwarding is correct, but you have missed some ports. Can you share firewall file config?