Stick Up Cam Elite motion detection not always working

I have a Stick Up Camera (Gen. 2) mounted about 2 feet above my garage door and directed downwards onto the driveway which is about 40ft long. I have set the detection zone to encompass all of the driveway asphalt. If a car drives into the detection zone and stops, recording is not triggered during the day (night I'm not sure). However, if a rabbit runs across the detection zone (near the garage door) it is. Obviously I don't care about the rabbits but I want to capture cars. I have motion detection enabled, motion sensitivity to 1 click below maximum, and smart alerts disabled. I have looked thru some the Ring support docs but they haven't helped. Some talk about placement of the camera, but my assumption is that the position of the camera and the position of detection zone are not critical since this camera should detect motion based on video analysis and not heat (PIR). There is good contrast between the car and the asphalt so any motion within the zone should trigger recording. Also, the camera is hard-wired to my network so wi-fi is not factor. Any advice?