FCM ios push-уведомление в форме xamarin, когда приложение закрыто (проведено)

Question

В настоящее время я работаю над push-уведомлением xosmarin form ios app. если приложение закрыто (перевернуто), то DidReceiveRemoteNotification не вызывает.

полезная нагрузка данных такая же, как на стороне сервера ,

private void SendMessage (строка [] MessageTokenArray, строка TextMessage)

    {
            var dataIOS = new
                {
                    // to = MessageToken,
                    registration_ids = MessageTokenIOS,
                    content_available = true,
                    priority = "high",
                    data =  new
                    {
                      body = body1,
                      title = eventname,
                      click_action = "OPEN_ACTIVITY_1",
                      priority = "high",
                      tag = "\"1\""
                     },
                     notification = new 
                     {
                        title = eventname,
                        text = TextMessage,
                        sound = 1,
                        vibrate = 1,
                    },
                };
                SendNotificationn(dataIOS);
        }
    }

в xamarin ios

public override bool FinishedLaunching (приложение UIApplication, параметры NSDictionary) {

        CrossFirebasePushNotification.Current.RegisterForPushNotifications();
        FirebasePushNotificationManager.Initialize(options, true);
        FirebasePushNotificationManager.CurrentNotificationPresentationOption = UNNotificationPresentationOptions.Alert | UNNotificationPresentationOptions.Badge | UNNotificationPresentationOptions.Sound;

        CrossFirebasePushNotification.Current.OnTokenRefresh += async (s, p) =>
        {
            //save token in server db
        };
        CrossFirebasePushNotification.Current.OnNotificationReceived += async (s, p) =>
        {
            //save data in local db
        };

        CrossFirebasePushNotification.Current.OnNotificationOpened += (s, p) =>
        {
            //do something
        };
        return base.FinishedLaunching(app, options);

    }

public override void DidReceiveRemoteNotification (приложение UIApplication, NSDictionary userInfo, Action завершениеHandler)

{ FirebasePushNotificationManager.DidReceiveMessage (UserInfo);

completionHandler (UIBackgroundFetchResult.NewData);

}