What is a sticky notification?
In Android, notifications can be set to be "onGoing", which means they are sticky and cannot be swiped away. Some common examples are music players, and Android's own update notifications.
Why do I keep not getting notifications?
Check the notification settings for your app. Ensure notifications are turned on and set to the correct sound or vibration. Restart your Android device. A restart can often fix temporary software glitches that may be causing problems with notifications.