Attached Actors in the World Outliner are Becoming Unattached Upon Changing and Compiling the Blueprint

Making a change in a blueprint and then compiling it causes any actors that are attached to it to become unattached.

1. Open the editor
2. Create a new Actor
3. Place two instances of it in the level
4. In the World Outliner, attach one of the instances to the other
5. Open the blueprint
6. Add a static mesh component
7. Compile

Result: The actors become unattached after compiling the blueprint after making a change.

Expected: The actors would remain attached.