ChildActorComponent requires lighting to be rebuilt each time level is opened

I was able to reproduce the loss of cached lighting data on latest, however I did not hit the code that emits the warning message as noted in the thread.

1. Launch UE4 editor (any project).
2. Create a new Blueprint class based on StaticMeshActor.
3. Select the StaticMeshComponent and set the StaticMesh to 'Shape_Cube'.
4. Compile and save the Blueprint class.
5. Create another new Blueprint class based on StaticMeshActor.
6. Add a ChildActorComponent and attach it to the StaticMeshComponent.
7. Select the ChildActorComponent and set the Actor class to the first Blueprint class, and change the Mobility to 'Static'.
8. Compile and save the Blueprint class.
9. Add an instance of the second Blueprint class to the current level.
10. PIE, and notice that lighting needs to be rebuilt.
11. Exit PIE and build lighting.
12. PIE again, and notice that lighting no longer needs to be rebuilt.
13. Save and close the current level.
14. Reopen the current level. PIE and notice that lighting once again needs to be rebuilt.

Expected result: Cached lighting data is preserved and lighting does not have to be rebuilt after reopening the map.