Should at least be getting an error, otherwise it's not reading anything.
I've dropped mine, and subisquently had it quit. Pulling it apart, cleaning, and re-assembling got it going again. Ive had dust fall in mine, too. It's hard for it to pick up smaller projectiles. And it seems some shapes or coatings may be harder to pick up, too. Like a more reflective finish?
Anyhow, mine works great with those lights. Just have to shoot dead center across bother sensors