GetPlayerPawn returns NULL in some cases

First off, im a beginner in unreal engine and blueprints.

I encountered following error:

Wen i start the game with “play in new window” with for example 4 clients (one is the host), the GetPlayerPawn function in the CameraPawnController Blueprint initialisation returns null for all 3 clients. Therefore the camera pawn is not initialized and produces more followup errors.

Now comes the strange part: If i spam-click the “play in new window” button all the new windows are opening minimized and if i maximize them, no client has the error.

CameraPawnController Event BeginnPlay:

The Makro called:

Ingame Print results:

275949-inagame-print-statements.png

Log (first fiew lines only because the errors are looping):

Can someone help me?