Blueprint with ChildActorComponent causes BP set as child to become dirty on open/edit

If a blueprint has its root component set in code, adding that blueprint as the child actor component of a second blueprint will cause the first to become dirty anytime the second is opened or edited. This does not occur if the root component is not defined in code.

Regression:
Yes - first blueprint does not become dirty in 4.14 Binary (CL 3249277)

1. Open UE4 Editor (any project)
2. Add code based on actor (MyActor)
3. Add the following to MyActor.h

   UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = test)
   	UStaticMeshComponent* Meshy;
   

4. Add the following to MyActor.cpp (in constructor)

   Meshy = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("Meshy"));
   RootComponent = Meshy;
   

5. Compile
6. Create blueprint based on MyActor (MyActorBP)
7. Create blueprint based on Actor (ActorBP)
8. Add Child Actor Component to ActorBP
9. Set Child Actor Component to MyActorBP
10. Save All so neither blueprint is dirty
11. Make an edit to ActorBP

Result:
MyActorBP becomes dirty

Expected:
Editing one blueprint does not dirty another that is not a child.