Ring Stickup Cam can't see White BMW...

I have several Stickup cams and the one on my garage sees everything... except my wife's car. The cam picks up motion from cats crossing the driveway, moths flying at night, the neighbors picking up mail at the end of the driveway etc... My driveway is approximately 75 feet and when the mail is delivered, the camera picks up the motion. Same for the garbage collector. But, my wife's white BMW is invisible. She can leave the garage and back out and the camera never alerts or records. Same when she returns. The camera picks up everything else but her car.Is this a flaw in the camera?