Problem Unpossessing Character

I have a parent character that has a few child characters. One of those child is the Default Pawn Class in the Game Mode.
In my parent character I have these nodes:

So, when I click on a child, I unpossess the previously possessed one. The unpossessed childs are controlled by an AIController.

This is working perfectly for every child but the Default Pawn Class. It is not moving when I am possessing another child… which I guess it means that Player Controller is unpossessing the default pawn, but AIController is not possessing it…

Any idea on how to solve this problem?

Thank you in advance!