Subclass disappears from class variable drop-down on re-open

Subclass disappears from class variable drop-down upon reopening the project. There is a workaround for the issue but it is strange in nature. Opening the level blueprint and adding the node in screenshot_001 will add the subclasses back to the menu (and work when opening the project)

Regression:
This issue occurs in 4.15, 4.14.3, and 4.13.2 Binary versions

1. Create a new blank project (No template or starter content)
2. Create a new Actor class blueprint > Name it "Parent"
3. Right click Parent and select the option "create child blueprint class" > Name it "Child"
4. Duplicate Child and name the new one Child_Duplicate
5. Create a new Actor class blueprint > Name it "Actor_BP"
6. Open Actor_BP
7. add a new variable of Parent and make it a Class > name it Parent_VAR
8. Make Parent_VAR editable and expose it on spawn
9. Compile and save Actor_BP
10. Add Actor_BP to the level and go to its details panel
11. click the drop-down menu for Parent_VAR (Expected Result)
12. Save all > Name open level "TEST" > and close the project
13. Re open the project > Open level TEST and select Actor_BP
14. Go Parent_VAR in the details panel and click the drop-down menu

Result: Child and Child_Duplicate are not longer available to select as options
Expected result: Child and Child_Duplicate are still available to select as options