Following instructions from Ryan I made a setmaterial blueprint for a cube. That works nicely.
Then I alt-dragged the placed blueprint to make three, and played, and they go nuts. One will work, one will half work and the other will flash. Am I doing something that isn’t supposed to be done? Or do I need to do something extra to make the blueprint work in every instance? Or maybe affecting one affects its buddies?
Glad you worked it out! Note another way to restrict what is triggering your BP is to modify the collision settings of the box components to only touch pawns, and ignore everything else.