If you are wondering why the Check-In button on your device is not working, it may have something to do with how long you are pressing the button down for.
The physical check-in button on your ZOLEO device works when you press it momentarily. It may not work if you are pressing down the button for a second longer.
Once you press the Check-In button momentary, it should give you a confirmation tone along with flashing green LED lights. This means that the check-in message has been generated successfully.