SetMobility break Attachment in the Constructor

In the constructor script I’m trying SetMobility for the StaticMeshComponent.

But after load Editor - I lose my StaticMeshComponent from parent SceneComponent, its reseting to World Origin (0,0,0) and can’t move with parent in the Editor when dragging.

what could I missed?

OnConstruction works fine

void ATomMachine::OnConstruction(const FTransform& Transform)
	//UE_LOG(LogTemp, Warning, TEXT("AMyActor::OnConstruction() called"));