Why isn't EventBeginPlay firing for one child?

I am trying to use an event dispatcher to make all enemies die and pickups go away when a certain thing happens. This works for everything execpt for a two classes: RobotCharger, which is a child of RobotParent, and ObjectivePickup, which is a child of PickupParent. It works perfectly well for RobotShooter and the other pickups which are also a children of the same classes. I have been able to track down the origin of the problem using a print statement, and the problem is that the begin play event does not fire for RobotCharger or ObjectivePickup. Why is this and how can I fix it?