Cannot save blueprint using custom blueprint function library after a hot reload

When a blueprint contains a function call from a custom blueprint function library, preforming a hot reload will prevent the blueprint from saving stating that the graph is linked to private object in an external package.

1. Open UE4 Editor (Any Project)
2. Add code to project based on BlueprintFunctionLibrary (CustomLib)
3. Add the following to CustomLib.h

   public:
   	UFUNCTION(BlueprintCallable, Category = Test)
   		static void TestFunc ();
   

4. Add the following to CustomLib.cpp

   void UCustomLib::TestFunc()
   {}
   

5. Compile the code
6. In the editor, create a blueprint based on Actor (ActorBP)
7. add TestFunc node in event graph
8. In Visual Studio, add float variable
9. Use editor compile button to preform hot reload
10. Open ActorBP and click the save icon

Result:
Blueprint fails to save. "Graph is linked to private object..." message

Expected:
Blueprint saves after a hot reload

Blueprint macro libraries referencing C++ functions cause 'Graph is Linked to External Object' error on hot reload