I've played on this server for a while. with the last update (0.16.51) I can't connect to the server until I initiate a connection from some other service. We also have a mc server running on that box. Once I connect to the mc server or the SSH terminal, then I can connect the Factorio without issues.
its the oddest thing.
I have check the firewall on the server, my home firewall, windows firewall. I wonder if something change in the connection initiation code on factorio.
Anyone else have that issue?