UE4 nested component failed in blueprint

[Kenculate (Saeid Gholizade)]

I am trying to create a custom USceneComponent with another USceneComponent as its child,

UPROPERTY(VisibleAnywhere, meta=(AllowPrivateAccess="true"))
USceneComponent *comp1;

comp1 = CreateDefaultSubobject<USceneComponent>(FName("comp1"));
comp1->SetupAttachment(this);

then this is what I will get if I add it to an actor blueprint,

https://forums.unrealengine.com/core/image/gif;base64
​
but if I add it to a c++ actor it will appear as expected

USceneComponent *myscene = CreateDefaultSubobject<UMySceneComponent>(FName("myscene"));
myscene->SetupAttachment(root);

any idea to fix this is appreciated.