I figured I couldn't be the only one who's seen this. It happens randomly but fairly regularly and if it happens once in a round, it usually occurs more than once after that.
I've had it happen not just on regular ranked rounds, but in tournaments on faster greens too. I seldom use the practice mode. It's almost as if the game shifts to a lower meter even when I don't change the scale manually. It looks like I'm shooting on a 30 scale, but actually hitting a 15 scale.
I'll try to keep track the next time I'm setting a distance close to a scale break and see if it happens under those circumstances.