New Entry Sensor does not light up

I recently upgraded from the SS2 to the SS3 system, and while installing the new system I noticed that 1 of the Entry Sensor's does not light up/flash blue as the magnet comes in and out of contact with it. I do hear the base station "chime" when the sensor and magnet are within proximity of each other, however the blue light does not blink on it. I have tried swapping out the battery with a known good battery and even removed the device from the keypad menu and re-added it again and it still does not light up. Is the sensor defective? The other 3 entry sensor's work just fine.

I called Customer Service last night but gave up after being on hold for a half hour. I also emailed them, but not sure whether I will get a response. Any feedback is appreciated! Thanks.