S Health pedometer calibration between number of steps and distance is wrong.

A

AC Question

On 28th Dec 2015 S Health recorded 5.31 miles for 12868 steps = 2,423 steps per mile (which seems right)
But on 10th June 2016 on another walk it said I had walked 14.81 miles for 19204 which is 1297 steps per mile (which can't be right as 1760 yds = 1 mile)
So problem is the calibration between number of steps and distance as using the 2,423 steps per mile factor would be 7.9 miles which seems right for the walk we did on 10th June.