Video Doorbell 2 not sensing person within motion zone

Installed Video Doorbell 2 in place of original doorbell at front door on a raised porch. Entry steps are on the opposite end of the porch coming up from the side. Mounting wedges are installed to aim the camera as best as possible toward the steps, still including the landing area. Motion detection zones are outlined around the approach steps and the porch landing area. In spite of multiple and seemingly endless iterations of settings, the app will not detect a person unless they are directly in front of the camera. The approach steps are on the side of the detection zone, but still clearly within the zone. Sometimes the app detects motion on the street about 40 feet away in spite of being set only for detecting people. Does anyone have info about this kind of issue? My next step is to custom build (3d print) a right-angle mount to aim the camera directly at the steps to put the view in the middle of the detection zone.