How to assign component to Uproperty from within class defaults

Hello,
Mind telling me why its not working in my case?


UPROPERTY(Instanced, EditInstanceOnly, BlueprintReadWrite, meta = (AllowPrivateAccess = "true"), Category = Attachment)
	USceneComponent* SomeComponent;
	UPROPERTY(Instanced, EditInstanceOnly)
	USceneComponent* SomeComponent1;

None of them is showing in details panel in class defaults