A month or two ago looks like the recognition software was updated. Now when I ask to only show notification for Person, it keeps showing me every car that passes by. I assume it may be picking up the driver in the car. This defeats the whole purpose. Makes notification use very disruptive.
Actually it’s the motion of the moving vehicle that is being detected. You should fine tune your detection zone and if you have a subscription, turn off the detection events you don’t want. Assuming you have a subscription for smart events for person detection. I highly doubt a person in a vehicle is being detected.