Instance changes no longer propagating to ChildActor after updating from 4.11.2

Function parameters do not appear to pass the correct information after updating from 4.11.2

1. Download the attached project
2. Open project as a copy for a newer version of then engine
3. Open the level "ChildActorComponent_TroubleIn4-12-2"
4. Select the "BP_ActorWithChildActorComponent"
5. In the details panel try and change the "Scattered Mesh" setting
6. Notice that the static mesh does not update

Expected: The Actor would update to match the mesh that was selected
Result: The function (Set Grid Settings) in "BP_ActorWithChildActorComponent" does not pass the correct values