Android notifications not always delivered

Question

I'm writing my android application, which should always show a notification every day at 10:00 AM, no matter what. I use an alarm service to fire notifications at a specific time.

I set notifications to fire in two cases:

• when I open the app, I set the alarm service to fire at the nearest 10:00 AM
• when I receive notifications, I set the alarm service to fire the next day at 10:00 AM

The problem is: When the interval between the moment when I set alarm service and the actual alarm is greater than approx 12 hours, I just don't receive that notification. If the interval is smaller - I do. But I checked the logs, the alarm service is scheduled properly and for the correct time no matter how I set notifications.

I expect the problem is in the battery optimizer, but I don't know how to verify (and fix) that.

What I tried In Android I've added my app to exceptions, allowing it to run in the background.

Tested on Huawei P30 Pro, Android 10.

Attaching the code how notifications are scheduled

public class AlarmBroadcastReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        // display notification 
        NotificationController.scheduleNextNotification(context);
    }
}

public class NotificationController {

    public static void scheduleNextNotification(Context context) {
        Intent myIntent = new Intent(context, AlarmBroadcastReceiver.class);

        PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, myIntent, 0);
        AlarmManager alarmManager = (AlarmManager) context.getSystemService(ALARM_SERVICE);

        long notificationTime = getNotificationTime(new Date());

        int alarmType = AlarmManager.RTC_WAKEUP;
        alarmManager.setExactAndAllowWhileIdle(alarmType, notificationTime, pendingIntent);
    }
}