No mid-range motion detection?!

We have had our doorbell installed for a number of months. Motion detection settings don't work very well. 1) A person 8 feet from doorbell is detected. 2) A car moving 25mph on the street 40 feet away is detected. 3) Walking in the front yard in the 8-40 feet zone OR a slower moving car are NOT detected. No way to capture slower moving vehicles or people in our yard.Have tried all of the settings with no success. Is there any technical support path to improve performance? Seems like a simple detection algorithm update with the reliable detection of cars at 40 feet. Quite disappointed at this point.