I running into a similar problem when worked with BP_ThirdPersonShooterAI in ThirdPersonKit.
TPKit using PawnSensingComponent in a BP_Sensing_Pawn which is used as a ChildActorComponent in BP_ThirdPersonShooterAI. This is causing the AI not working properly when spawned because the BP_Sensing_Pawn as sub-class of APawn will try to spawn its default AIController when Initialized which is happened within the construction scripts of the ChildActorComponent and it’s forbidden as mentioned here
the solution is to spawn an AIController manually and posses the BP_Sensing_Pawn, then all works well.