Map Check error when parenting an actor to a child actor in Scene Outliner

Map Check will generate an error when an actor is attached to a child actor in the Scene Outliner. At runtime, the attachment seems to work as intended so it's only a Map Check issue. The error reads something like:

Actor /Game/MyMap.Cube has an invalid reference to E815E3AC4A7EA3EC50BD0893082B1B38  

or (attached actor) has an invalid reference to (actor with child actor component).

Expected: Map check does not produce an error when an actor is attached to a child actor.

See repro video.

• Create a blueprint with a ChildActorComponent
• Set the child actor class to StaticMeshActor, or any other valid actor class
• Drag an instance into the level
• In the Scene Outliner, parent any actor to the child actor
• Do Build > Map Check, observe the error message