I can not show LoadingScreen using FLoadingScreenAttributes

I wrote the c ++ code by referring to the link above.
As a result of debugging, function binding is not a problem However, LoadingScreen did not show on the screen.

This is my code.

void UEditorGameInstance::SetLoadingScreen(UUserWidget* NewLoadingWidget)
	LoadingWidget = NewLoadingWidget;

void UEditorGameInstance::Init()
	FCoreUObjectDelegates::PreLoadMap.AddUObject(this, &UEditorGameInstance::BeginLoadingScreen);
	FCoreUObjectDelegates::PostLoadMap.AddUObject(this, &UEditorGameInstance::EndLoadingScreen);

void UEditorGameInstance::BeginLoadingScreen(const FString& MapName)
	FLoadingScreenAttributes LoadingScreen;
	LoadingScreen.bAutoCompleteWhenLoadingCompletes = true; 
		LoadingScreen.WidgetLoadingScreen = LoadingWidget->TakeWidget();
		LoadingScreen.WidgetLoadingScreen = FLoadingScreenAttributes::NewTestLoadingScreenWidget();


The function of ‘SetLoadingScreen(UUserWidget*)’ is regist my LoadingScreen widget.
Where did I get it wrong? Am I misunderstanding? How to make LoadingScreen?

I found one thing by referring to the Shooter Game today.
This LoadingScreen did not work on the editor screen.
Tested through the StandAlong Game, it worked.