I had the same problem with mine. I found that the speed sensor was out of adjustment. Only took me 2 years to get mine dialed in and worked like should. I watched a lot of videos on you tube to learn about the monitor. That coil pickup is very sensitive. I set the monitor to miles per hour and keep playing with the calibration number to get it to match the tractor mph.  When I got that to match it worked like it supposed to acreage was right on population was right on. 
    I would power up the monitor and go through all the configuration steps and they were set right as soon as I started moving it would say the seed hoppers were empty witch keep me puzzled. 
    I bought a used planter that came with no monitor and bought the kpm3  from a guy the switched to agleader  then  when I went to lean the sensors it would beep but when I went to the plant screen it would not recognize the sensors. Found out I needed to buy all new sensors with the blue plug. 
   Like I said it only took me 2 years of research and hair pulling to figure it out now I couldn’t be happier with it.
    I think my speed number was 60225  friend has a 3600 16-31 like mine his number is 60300.
      Hope this helps.