Has Any User Focused Descendants returns true even if all children have been removed

HasAnyUserFocusedDescendants returns true even when all children have been removed.

1. Open the editor
2. Create a new widget blueprint
3. Add a vertical box to the designer tab
4. Place a few buttons within the vertical box
5. Create the blueprint in the attached image
6. Play in Editor
7. Click one of the buttons that don't do anything to give focus
8. Click the button that removes all children
9. Notice that the print string continues print true

Expected: HasAnyUserFocusedDescendants would return false when no children exist
Result: HasAnyUserFocusedDescendants returns true even when no children exist