People only Mode detecting flag

Our Doorbell Pro faces front yard and is in the middle of a 34' long porch. I have the zone set to not detect peopl on the sidewalk, but will detect front yard and driveway. We put out our flag, and when it waves the doorbell senses it. The flag is about 8' in front of the doorbell Pro. Your one post says the People Only mode looks for heat sense (_HEAT SIGNATURES The reason your device is looking for heat signature movement is to try and lessen the number of false motion alerts you receive. If it alerted you to all movement in front of your door (e.g. your neighbor's flag) you would likely get sick of those constant false alerts. Your sensors are specifically l...)_ Why is my flag being picked up?