I have a Minecraft Server running on a computer of my LAN. It's the actual minecraft_server.jar, not a shared single player world, and I can connect to it from other devices on the LAN. I opened its port in the firewall and set up port forwarding so that it's accessible from the outside.
However, from outside the LAN, I get "connection refused". Online scanners (like this one) say that the Minecraft Server port is open and can even detect the version of Minecraft, so the port seems to be forwarded correctly (I set it up in the router's settings), so I really don't understand how the connection can be refused.
The exact message I get is "Connection refused : no further information".
server.properties file is the default one, with juste the difficulty changed to 2.
What can cause this "Connection refused" message ?