On my 264 deadbolt, when the door is closed and the Kwikset button is pressed to lock the door, the lock emits a system alert. When the door is open and the Kwikset button is pressed to lock the door, there is no system alert.
Make sure that the hole in the door frame behind the strike is drilled at least 1 inch (25 mm) deep. Also make sure the strike plate is aligned with the latch bolt. If needed, reposition the strike.