"Has Authority" problem if Server and Client share same IP adress over steam


I am currently testing my multiplayer game via Steam Online session.
It works all great (can host and join server), except that “Has Authority” and “IsServer” are not working as expected.

  1. Host Server with PC 1 over Steam
  2. Join with PC 2 (Client) over Steam
  3. PC 1 (Server) spawns actor and PC 2 (Client) posses it
  4. “Has authority” and “IsServer” are not working for the actor (server spawned) , always return “Authority” on “True” on Client side.

It all works fine, if I test it via dedicated Server in LAN.

So I thought it could be a problem, that the both PCs having the same external IP adress and thus cannot distinguish between server and client?
Did anybody has a similar problem?
If yes, is there any chance, I can test multiplayer on Steam with only one IP adress?

Thanks in advance,


Do you use the same steam account or two different steam accounts? That could be the Problem.