Both OnComponentBeginOverlap and OnComponentHit have an execute pin (the white thing on top) that drives everything after it. Your Apply Damage function only runs when your actors overlap, but not on hit. Similarly, the impulse is most likely empty as your nodes are now.
You have two options:
- Connect the execute pin from OnComponentHit to Apply Damage and use that with the hit impulse or
- Remove the Location/Impulse pins and put a fixed amount (such as an upwards pointing vector) in there.
I’d probably go with 2., since the box is meant to be hit from below; not from the sides or elsewhere.