"Matadata" Ustruct Name Incorrectly became PascalCase on Packaging

I have a struct:

USTRUCT(BlueprintType)
struct MY_API FFooTest
{
	GENERATED_BODY()

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Foo | Test")
	TMap<FString, FString> Metadata;
};

When I run from Editor, the field “Metadata” name correctly becomes “Metadata”.
But, when I run from a packaged, the filed “Metadata” name incorrectly becomes “MetaData”.
When I check on
FField::FField(FFieldVariant InOwner, const FName& InName, EObjectFlags InObjectFlags)
the field “InName” value already becomes “MetaData” in the packaged.
So, what is the root cause that makes the name “Metada” become PascalCase (“MetaData”) ?