FTransform does not show up in the editor

I suppose your struct locates in a UCLASS() as member variable.

Without any initialization it works for me:

USTRUCT(BlueprintType)
struct FMyStruct
{
	GENERATED_BODY()
	
	UPROPERTY(BlueprintReadWrite, EditAnywhere)
	FTransform Bar;
};

UCLASS()
class CONTENTEXAMPLESCPP_API AMyActor : public AActor
{
	GENERATED_BODY()

	UPROPERTY(EditAnywhere)
	FMyStruct Foo;
	
public:	
	AMyActor();

protected:
	virtual void BeginPlay() override;

public:	
	virtual void Tick(float DeltaTime) override;
};

307597-answerhub-struct-transform.png