Gen 2 Motion Sensor - Very poor range in detecting motion (or defective?)

Just installing new Gen 2 devices with my existing Gen 1 Alarm System. Added a Gen 2 motion sensor to my existing Gen 1 Alarm System with no issues. I tested motion detection on this new Gen 2 motion sensor. I put it next to a Gen 1 motion sensor. For every movement, the Gen 1 motion sensor (on medium sensitivity) could detect motions, while the Gen 2 motion sensor (on high sensitivity) could not. I had to come to as close as 6 feet, then the Gen 2 motion sensor was finally able to detect motion. Is this a defective Gen 2 motion sensor unit I have, or the new Gen 2 unit just performs poorly compared to Gen 1 motion sensor? This very short range of 6 feet on the Gen 2 motion sensor is totally not acceptable.