I haveily modified my version of building escape so picking apart my project a little here. (Fortunatly i kept my old pawn BP)
If i remember rightly at the stage your at its the actor that triggers the pressure plate to open the door.
I think the reason your default pawn is not working is because you missed turning on “Simulartion generates hit events” or Generate Overlap events is off (I forget which one it is or both 
), This is under the collision component.
