Starting in Android 8.0 (API level 26), all notifications must be assigned to a channel or it will not appear.
NotificationChannel is a new notification feature on Android 8. Unfortunately, it had a bug which is vibration cannot be disabled normally.
The trick is enabling vibration and setting empty pattern.
NotificationChannel channel = new NotificationChannel("id", "name", NotificationManager.IMPORTANCE_LOW);
channel.setVibrationPattern(new long[]{ 0 });
channel.enableVibration(true);
Debug tips
You've implemented the tricks above, but your notification vibrates still?
You have created the channel in your application. Once channel is created it cannot be changed. You need to either reinstall the app or create a channel with new channel ID.
All configs applied to NotificationChannel is immutable.