Hi ,
what do you mean by “not colliding”? Is the OnHit Method ever being called? If it is not being called, you should check if the collision settings are correct! (Open the Blueprint → Components → Mark your colliding box/sphere and check if generate Hit events is checked and if its Collision Channels are set correctly!)
[You might check out: Collision in Unreal Engine | Unreal Engine 5.2 Documentation]
Good luck!