Child class references are not shown after restarting the editor

Child class references are not shown after restarting the editor. However, the other reference will show up if the child blueprint is currently open.

1. Download the attached project
2. Open the project
3. Click the "Spawner" actor in the level
4. Click the New Var 0 drop down

Result: Only the Parent class in available (Core_Char).
Expected: The child blueprints of "Core_Char" would also show up in the list