Player doesn't possess actor

I have the problem that my player controller does not possess the pawn on startup.
When hitting Possess it seems like it tries to possess a default pawn, which I did not assign because I have a custom game mode script. In this script I use a Possess node but the Get Controlled Pawn of my player controller returns None.

237742-nopossess.gif

So I copied the blueprint to another project, it does not seem to be the issue.

When migrating the blueprint to another project it works.