Default Widget Reference Value in Parent Widget Resets on Compile

Is M Sub Widget Test a UUserWidget*? I had the same issue with my class, just had to change it to be TSubclassOf and then construct it in the constructor like this:

if (WidgetClass)
{
		UUserWidget* Widget = CreateWidget<UUserWidget>(GetWorld(), WidgetClass);
		if (Widget)
		{	
            Widget->AddToViewport();
        }
}