1 camera works perfectly, the other malfunctions and eats expensive Lithium batteries every 3 days! Someone did not do a good job of checking the functions on the 1 camera. You may be better off spending more and buying only new cameras. I now have 4 functioning cameras. One early generation camera failed after 3 years: the other camera is fine. One camera was damaged by a vengeful Roadrunner. He despised having a video of his mating ritual!
Sorry about the issue with the one camera. Did you double check the settings to make sure it was on motion activation only?
If no luck, make sure you reach out to customer service.