Why does changing the channel ID and channel name in flutter_local_notifications affect whether the notification message is displayed?

Question

I am using the example from flutter_local_notifications version v18.0.1: https://github.com/MaikuB/flutter_local_notifications/tree/flutter_local_notifications-v18.0.1/flutter_local_notifications/example

When I change the channel ID and channel name from 'repeating channel id', 'repeating channel name' to 'your channel id', 'your channel name', the message is displayed. However, when using the original channel ID('repeating channel id') and name('repeating channel name'), the notification only shows a small icon without the message(When I pull down from the top of the device, I can view the details of the notification.).

Here is the code where the message is not being displayed: https://github.com/MaikuB/flutter_local_notifications/blob/flutter_local_notifications-v18.0.1/flutter_local_notifications/example/lib/main.dart#L1867

Future<void> _repeatNotification() async {
 const AndroidNotificationDetails androidNotificationDetails =
     AndroidNotificationDetails(
         'repeating channel id', 'repeating channel name',
         channelDescription: 'repeating description');
 const NotificationDetails notificationDetails =
     NotificationDetails(android: androidNotificationDetails);
 await flutterLocalNotificationsPlugin.periodicallyShow(
   id++,
   'repeating title',
   'repeating body',
   RepeatInterval.everyMinute,
   notificationDetails,
   androidScheduleMode: AndroidScheduleMode.exactAllowWhileIdle,
 );
}

After changing to 'your channel id', 'your channel name', the message is displayed:

Future<void> _repeatNotification() async {
  const AndroidNotificationDetails androidNotificationDetails =
      AndroidNotificationDetails(
          'your channel id', 'your channel name', // Change ID and name
          channelDescription: 'repeating description');
  const NotificationDetails notificationDetails =
      NotificationDetails(android: androidNotificationDetails);
  await flutterLocalNotificationsPlugin.periodicallyShow(
    id++,
    'repeating title',
    'repeating body',
    RepeatInterval.everyMinute,
    notificationDetails,
    androidScheduleMode: AndroidScheduleMode.exactAllowWhileIdle,
  );
}

I searched for occurrences of 'your channel id' in the code but couldn't find any specific conditions for displaying the notification message.

I also checked the Android documentation on channels: https://developer.android.com/develop/ui/views/notifications/channels

but I still don't understand why changing the channel ID and name made the message appear.

'repeating channel id','repeating channel name': The message is not displayed (sound plays, and the small icon is displayed on the device). When I pull down from the top of the device, I can view the details of the notification.	'your channel id','your channel name': The message is displayed (sound plays, and the small icon is displayed on the device). When I pull down from the top of the device, I can view the details of the notification.

---

The reason I changed it to 'your channel id', 'your channel name' is that it was used in other parts of the code where the message was successfully displayed: https://github.com/MaikuB/flutter_local_notifications/blob/flutter_local_notifications-v18.0.1/flutter_local_notifications/example/lib/main.dart#L1052

Future<void> _showNotification() async {
 const AndroidNotificationDetails androidNotificationDetails =
     AndroidNotificationDetails('your channel id', 'your channel name',
         channelDescription: 'your channel description',
         importance: Importance.max,
         priority: Priority.high,
         ticker: 'ticker');
 const NotificationDetails notificationDetails =
     NotificationDetails(android: androidNotificationDetails);
 await flutterLocalNotificationsPlugin.show(
     id++, 'plain title', 'plain body', notificationDetails,
     payload: 'item x');
}

So, I simply referenced the code where the message was displayed, I don’t fully understand why it works. I would like to know the underlying mechanism.

---

At first, I thought that importance: Importance.max and priority: Priority.high might be related, so I tried various things. However, in the end, the factor that mattered was the channel ID and channel name.