Intermittent Cable Limiter Switch Problem

Anyone else experience something like this with the Alpine Flex and cable limiter switch? I installed the cable limiter switch for my plow last night and just tested it by moving the magnet up and down by hand and everything was perfect. Today I put the Magnet on the plow tested it and it was flawless, tried it half a dozen times minimum and it stopped a quarter of a inch from the plow frame every time! I literally backed 25 feet out of my garage slowly and tried it again, failed, I stood on the side so I could watch it closely and nothing, it never stopped it and failed every time, I am sure the sensor could not have moved as I only backed out a few feet.

Any suggestions would be appreciated!