Overlapping isn't updated on replicated components after SetWorldTransform. Updating the transform on the Actor itself updates the overlapping as expected.
Reproduced in 4.10 and Main (CL# 2798114)
1. Create a new Third Person template project
2. Create a new Actor BP
3. Add a Box Collision component with Scale set to 2,2,2, Location 90,0,0
4. Disable Hidden in Game for the component
5. On Begin Play, Enable Input for Player Controller 0
6. Set Is Replicated to True for the Box component
7. On a key input, Switch Has Authority > (Authority) Set Relative Transform (Target = Box component)
8. Set the Relative Transform of the component to -180 of its original position
9. In the ThirdPersonCharacter BP, Event ActorBeginOverlap > Cast to the Actor BP > Switch Has Authority > (Remote) Print String "Overlap"
10. PIE with Players set to 2
11. On the Server, press the input key to set the transform of the Box collision component
12. On the Client, run through the new position of the box collision component
13. On the Client, run through the prior position of the box collision component
The overlap is detected where the box collision component used to be and not where it currently is.
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