Swift didReceiveRemoteNotification() Firebase not being called

Question

After reading about this extensively, I cannot find the solution. I am sending cloud messages from Firebase to my ios app, but the method didReceiveRemoteNotification() is not being called at all, not when the app is in foreground and not in background. I tried sending from the firebase console, and also from postman using topics, and both don't work. I have integrated Firebase in the app, and uploaded certificate to Firebase, and I get no errors in the console. Just the notification isn't coming? I also added the capability of cloud messages.

This is what I do (from the Firebase tutorial) in appDelegate:

  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.

        FirebaseApp.configure()



        if #available(iOS 10.0, *) {
          // For iOS 10 display notification (sent via APNS)
          UNUserNotificationCenter.current().delegate = self

          let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
          UNUserNotificationCenter.current().requestAuthorization(
            options: authOptions,
            completionHandler: {_, _ in })
        } else {
          let settings: UIUserNotificationSettings =
          UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
          application.registerUserNotificationSettings(settings)
        }

        application.registerForRemoteNotifications()

        Messaging.messaging().delegate = self

        return true
    }


    func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
      // If you are receiving a notification message while your app is in the background,
      // this callback will not be fired till the user taps on the notification launching the application.
      // TODO: Handle data of notification

      // With swizzling disabled you must let Messaging know about the message, for Analytics
      // Messaging.messaging().appDidReceiveMessage(userInfo)

      // Print message ID.
      if let messageID = userInfo[gcmMessageIDKey] {
        print("Message ID: \(messageID)")
      }

      // Print full message.
      print(userInfo)
    }

    func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any],
                     fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
      // If you are receiving a notification message while your app is in the background,
      // this callback will not be fired till the user taps on the notification launching the application.
      // TODO: Handle data of notification

      // With swizzling disabled you must let Messaging know about the message, for Analytics
      // Messaging.messaging().appDidReceiveMessage(userInfo)

      // Print message ID.
      if let messageID = userInfo[gcmMessageIDKey] {
        print("Message ID: \(messageID)")
      }

      // Print full message.
      print(userInfo)

      completionHandler(UIBackgroundFetchResult.newData)
    }