I was able to get it working, means all users can see each other now.
Found an old thread here in the forum and this got it solved:
In admin console
Server > Mettings > Networking
Set your NIC
Set your IP
Websockets: disabled
IP Adress Mapping: did not use Amazon = Disabled
Local Adress: machine IP
Public Address: your Public
This entry solved it for me, as the server is natted
Rest of Settings : default
Just wanted to let you guys and others know.