Should you not receive any push notifications on your Android device or only receive push notifications when the app is open please try following:
Please login to our push server and reset the keys. Enter the new keys into your setting. Head to the maintenance section and remove the Mobile Device Tokens.
Logout from the app and login again, it will register the phone fresh.
Try again to receive push notifications.
In case that is not working for you, please head to your app settings:
Set notification volume on your phone to ON
Ensure notifications for the Live Chat 3 app are ON