Duplicate subobjects when you attach to an OptionalDefaultSubobject

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Character.h"
#include "FooActor.generated.h"

class USceneComponent;

UCLASS(BlueprintType)
class AFooCharacter : public ACharacter
{
   GENERATED_BODY()

   AFooCharacter(const FObjectInitializer& ObjectInitializer = FObjectInitializer::Get());
   
public:    

   UPROPERTY(EditAnywhere, BlueprintReadOnly)
   USceneComponent* TestSceneComp = nullptr;
};

// Copyright Epic Games, Inc. All Rights Reserved.

#include "FooActor.h"
#include "Components/SceneComponent.h"

// Sets default values
AFooCharacter::AFooCharacter(const FObjectInitializer& ObjectInitializer)
   : Super(ObjectInitializer)
{
   // Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
   PrimaryActorTick.bCanEverTick = true;

   TestSceneComp = CreateDefaultSubobject<USceneComponent>(TEXT("TestSceneCompName"));
   GetMesh()->SetupAttachment(TestSceneComp);
}