In my case, it's with HTH. It wasn't too short. Probably 8 ft, but going downhill, thus starting at a low speed. However, I repeated the shot and it worked.
I am having the same issue too in GSPro. Messing around in practice mode in GSPro on the green set 5 feet from the hole I noticed that many times the r50 was showing the hitting zone like a full shot when putting so its almost like it thinks its looking for a full shot. Even if you change clubs up and then back to putter it would do this. Once in a while it showed the regular putting hitting zone but still didnt read the putt right. One thing I noticed is that if you place the ball to the edge of the hitting zone closest to the r50 it will read some shorter putts. Overall I think there is a glitch that the unit is trying to read a full shot instead of a putt.
