UObject GC does not work in EditorSubsystem

Development Programming & Scripting
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1

What’s the problem

The Garbage Collection seems not work as I wished in EditorSubsystem.When I set one of the UObject pointer property in my EditorSubsystem to nullptr,it does not get garbage collected(or at least not trigger the destructor) even I wait long enough.The destructor get called when I enter other map or using hot compile.

How to reproduce the problem

Just create a new project in UE5.2.1,and create a custom EditorSubsystem and UObject as below.

UCLASS(BlueprintType)
class TESTPROJECT_API UTestEditorSubsystem : public UEditorSubsystem
{
	GENERATED_BODY()
public:
	UFUNCTION(BlueprintCallable)
	void CreateTestObject();
	UFUNCTION(BlueprintCallable)
	void DestoryTestObject();
protected:
	UPROPERTY()
	UTestGCObject* TestGCObject;
};

void UTestEditorSubsystem::CreateTestObject()
{
	TestGCObject = NewObject<UTestGCObject>();
}

void UTestEditorSubsystem::DestoryTestObject()
{
	TestGCObject = nullptr;
}

UCLASS()
class TESTPROJECT_API UTestGCObject : public UObject
{
	GENERATED_BODY()
	virtual ~UTestGCObject() override;
};

UTestGCObject::~UTestGCObject()
{
	UE_LOG(LogTemp, Error, TEXT("Destroy Successfully!"))
}

And create a EditorUtilityWidget to call CreateTestObject and DestoryTestObject(such as bind them to a button),the UTestGCObject’s destructor just not get called until open other map or recompile or close unreal editor.