are you sure the objects in the scene are of the type you are selecting?
can you put in some more Print strings:
-immediately after the BeginOverlap() including that OtherActor->Name (you might not actually be registering the overlap in the first place)
-after the GetAllActorsOfClass() maybe outputting the array length (the GetAllActorOfClass() might not be able to find anything that matches you class)