When running PIE with “Running Dedicated Server”, 2 players, then 1st player will not receive PlayerController. The 2nd, 3rd… etc are all OK. The 1st player’s PlayerController seems not even spawned. So the 1st player window can not be controlled.
This bug appears in the 4.12.5. It is OK in 4.12.3.
I tested with the ThirdPerson Template C++.