FSlateFontInfo - "Default parameter not parsed"

Hi.
(I am tipping my toes into unreal for the first time, so sorry if this is a noob question.)

For one of the custom user widgets I am trying to develop in C++ I would need a parameter of type FSlateFontInfo that carries a default value in a method - something like:

UFUNCTION(BlueprintCallable, Category = “DemoCategory”)
void SomeMethodName(
FSlateFontInfo TitleFont = ???)

For types like FVector2D, FLinearColor or EHorizontalAlignment I got it done. But Somehow when I add a default value for FSlateFontInfo, my project does not build anymore. I get the error

|Error||C++ Default parameter not parsed: TitleFont

I tried the following possibilities to initialize my TitleFont:

= FSlateFontInfo(FCoreStyle::GetDefaultFont(), 12);

and

= FCoreStyle::Get().GetFontStyle(TEXT(“NormalText”));

besides my own .generated.h my .h file contains all of these includes I added for this test and other tests:

include “CoreMinimal.h”
include “Blueprint/UserWidget.h”
include “Math/Vector2D.h”
include “UObject/ConstructorHelpers.h”
include “Fonts/SlateFontInfo.h”
include “Styling/CoreStyle.h”
include “Styling/AppStyle.h”

Or could it be I am missing a module in my build file?

PublicDependencyModuleNames.AddRange(new string { “Core”, “CoreUObject”, “Engine”, “InputCore”, “UMG” });
PrivateDependencyModuleNames.AddRange(new string { “Slate”, “SlateCore” });

Do you maybe have an advice for me?