The MP uses the downward facing sensors (in this case ultra sonics) to change the altitude. These only work up to 30'. So at 90', they won't work and the MP won't change altitude.YA I was up about 30 meters with my MP as there were a few tall spruce I was worried about - might have something to do with that. I a man gonna try it again this time walking the hill up and down - the closer the better so AT can not lose ya
I don't know how the M2P works as I don't have on and as I recall, it does not use ultra sonics.