Expose on Spawn Variables disappear after connecting promoted Class Variable on SpawnActor from Class node

The 'Expose on Spawn' inputs when calling the SpawnActor from Class node disappear if you promote the Actor Class to a variable.

You would think that as long as the promoted variable is referencing the same actor class, the 'Expose on Spawn' variables would remain exposed on the SpawnActor from Class node.

1. Open attached project.
2. Open the Level Blueprint.
3. Connect the 'BP Actor' class variable to the Class input on the SpawnActor node.

Outcome
The variables within the blueprint actor class which were marked as 'Expose on Spawn' are gone.

Expected
The variables remain as long as the blueprint actor class variable is referencing the correct blueprint class.