[4.14]UnloadStreamLevel is not working?

Hi! Im having a issue with the UGameplayStatics::UnloadStreamLevel , for some reason is not working,i followed this tutorial. Am i doing something wrong?
Thank you so much.

Note: If i use the unloadStreamLevel node(on BP) works perfectly.

ACharacter* myPersonaje = UGameplayStatics::GetPlayerCharacter(this, 0);
		if (miJugador == myPersonaje && mapa != "")
		{
			FLatentActionInfo latentInfo;
			UGameplayStatics::LoadStreamLevel(this, mapa, true, true, latentInfo);
			GEngine->AddOnScreenDebugMessage(1, 5.f, FColor::Red, FString(TEXT("loaded")));
		}

		if (miJugador == myPersonaje && mapaDescarga != "None")
		{
			FLatentActionInfo latentInfo;
			UGameplayStatics::UnloadStreamLevel(this, mapaDescarga, latentInfo);
			GEngine->AddOnScreenDebugMessage(1, 5.f, FColor::Red, FString(TEXT("unloaded")));

		}