Blackboard/BehaviourTree - Invalid movetolocation


i got a problem with me Blackboard / BHT or what ever the real problem is.

My BHT has simple states in it - Roaming and Follow Player -

finding a random point on the navmesh is working fine and the AI just moves there, but somehow he gets trouble setting a location vector to the player pawn.

The pawn gets detected, no problem, but the “movetolocation” will be invalid.

I first thought the problem is that the player pawn is moving along a spline so the location is false, but with a simple “ai move to (player in this case)” it just works and it follows.

I followed Tesla Dev’s AI BHT tutorial in case somebody cares ( Unreal Engine 4 Tutorial - AI Behaviour Tree - YouTube )

Hope someone can tell me whats wrong here :<