Can't join newly set up server

[kappatalist]

Hello

Me and a friend of mine are trying to create a private server me and him can play on. However, I am unable to connect to his server. He got his ports forwarded and everything. We tried moving the script to an actual dedicated server that had everything open. On the dedi I wasn’t able to join and he was still able to join. 

The only difference I can see is that he got his ports forwarded but that should be required by people who are not hosting a server? 

Server settings file:

“{
    "maxplayers" : 500,
    "name" : "DevTestServerPrivate", 
    "gamemode" : "roleplay", 
    "stream-distance" : 500.0,
    "announce" : true,
    "language" : "gb",
    "csharp" : "enabled",
    "port": 22005
}”

I was able to connect to the server once yesterday, but after a relog I couldn't connect to it again. 
Could anyone come with ideas why this is an issue? I am able to connect to some other servers that are using the same port as we are.