I guess setting it to PrivateLogin may block non-local incoming connections, but I don't really know as I'm not familiar with AXClassic stuff. Anyways, you could try that.
Also, to determine if it's just the login server that's having problems, you could try starting the world server and testing the connection at
http://canyouseeme.org/ for port 9000 and 5998/5999 for the login server.