Overlap Events Don't Work On ISM.

ISMs will generate Hit Events but not Overlap Events.

1. Add a cube with collision to a map and and set it to OverapAllDynamic.
2. Create a BP and add a StaticMeshComponent and InstanceStaticMeshComponent.
3. Add a single instance to the ISM and you can set the mesh to the same cube mesh.
4. Create an OnComponentBeginOverlap event for both the StaticMeah and the ISM and connect it to a debug PrintString node.
5. Add the BP to your map.
6. Press Simulate and move the BP over your placed cube in the map that was set to OverlapAllDynamic.
7. The StaicMesh will return the Print String event by the ISM won't.
8. You can test this further by enabling SimulationGenerateHitEvents on both the SM and the ISM and create OnComponentHitEvents. You will notice the ISM will generate Hit Events, but not Overlap Events.