ok.
how do you test if the Port gets forwarded?
on Windows use Windows Powershell the command is test-netconnection ip-address -port 7088
Looks like you can use the local IP of the GX to verify if a port is open or not.
Next thing to check: The software runs on a pc? If yes, does this pc have a firewall installed that will block incoming traffic?
I had to set rules on my windows machines to accept traffic from a different vlan. Took me a while to figure out why I was able to ping the printer on the other vlan but not the pc.
hope this helps