Instanced Editable Variables of type Blueprint Interface can't be set

This is a regression tested in //UE4/Release-4.27 cl 18319896

Instanced Editable Variables of type Blueprint Interface can't be set.

1. Create or open any project
2. Create and compile a Blueprint Interface named "BPI_Implement"
3. Create a Blueprint Actor named "BP_Triggerable"
   1. In Class Settings under Implemented Interfaces add BPI_Implement
   2. Compile, save, and close then Blueprint
4. Create a Blueprint Actor named "BP_Trigger"
   1. Add a variable of type BPI_Implement named "Triggerable"
   2. Set the variable to Instance Editable 
   3. Compile, save, and close the Blueprint
5. Place BP_Triggerable into the level
6. Place BP_Trigger into the level
7. Select BP_Trigger then in its Details panel select the drop down menu for the variable Triggerable

Expected Results:
BP_Triggerable appears and is selectable in the drop down menu. (from the ticket: "The dropdown list that should contain all blueprints that implement the Triggerable interface is empty and you can't set the Triggerable variable.")

Actual Results:
The drop down menu is blank.