I think your network setup is not working properly yet, perhaps the port is forwarded to a different machine or a different port, or a firewall could be stopping the traffic (although usually firewalls make the connections time out, rather than forcibly closed).
Start the server with "--log-comm" parameter, this will make it log all connections, each into a separate file in the "CommLog" folder. Look there if there is any connection attempt from the external address. If there is, great, the connection is getting through and something in the server keeps dropping it, post the logfile here. If there isn't one, it's your network setup that's at fault.
(btw interesting choice of topic title, that's exactly what I would call myself nowadays
)
Start the server with "--log-comm" parameter, this will make it log all connections, each into a separate file in the "CommLog" folder. Look there if there is any connection attempt from the external address. If there is, great, the connection is getting through and something in the server keeps dropping it, post the logfile here. If there isn't one, it's your network setup that's at fault.
(btw interesting choice of topic title, that's exactly what I would call myself nowadays
)