Spline Array created in code cannot be edited in a blueprint

If a TArray of spline components is created in code it is not possible to edit/add nodes to the spline inside a blueprint.

1. Open UE4Editor (any project)
2. Add code to project based on actor (MyActor)
3. Add the following code the header file:

 class USplineComponent; //between include statemens and UCLASS macro()

 UPROPERTY(EditAnywhere, Instanced, Category = "Path spline")
       TArray <USplineComponent*> PathSpline;

4. Add the following code to the constructor:

RootComponent = CreateDefaultSubobject<USceneComponent>(TEXT("SceneComp"));
       PathSpline.Add(CreateDefaultSubobject<USplineComponent>(TEXT("Path")));
       PathSpline[0]->AttachParent = RootComponent;

5. Compile the project
6. Create a blueprint based on MyActor
7. In the components hierarchy, select the Spline component

Result:
The nodes for the spline cannot be moved/edited.