Getattachedactors does not return the proper value when called from the Constructor

A user has reported that using GetAttachedActors in the Constructor does not work properly. If actors are attached in the editor, the function does not return the correct value when called in the Constructor.

Regression?: No
This occurred in 4.19 and 4.20

1. Download the attached project.
2. Open the project.
3. Add an Empty Actor, through the Place Mode menu, and add an instance of the ActorToAttachTo blueprint to the level.
4. Attach the Empty Actor to the ActorToAttachTo blueprint instance through the World Outliner.
5. Move the ActorToAttachTo instance (to ensure the Constructor is triggered)
6. Check the AttachedActors int variable in the Details panel.
   Result: The AttachedActors int is still set to 0.
   Expected: The AttachedActors int should be set to 1.