The key is turned to the armed position, but the device does not sound when the door opens and the door prop time expires.
Handed to wrong side.
Unplug battery and re-secured, 4 times is door prop mode. 5 chirps, the unit is not handed. Confirm the magnet is aligned correctly.
Disarm the device by turning your key clockwise. Look on the circuit board, there are to metal prongs with white lettering near them saying 'Mag Handing'. Short them together using something metal like a screwdriver or a key. The unit should beep 5 times. Reinstall the device with the door open, arm and close. You should hear 1 chirp and then the device is armed.
Link to installation instructions(handing detailed on page 6):
If JP1 is cut on the board, the unit is made to mount on the wall and use a external magnetic switch.