I walk the same route to work each day, however I have noticed that recently I am doing 500 - 1000 steps less each journey. This is an upto 25% difference.
I haven't noticed at what point the this happened, and if it was gradual, but it is certain;y lower since upgrading from my iPhone 6 on iOS 9 to an iPhone 7 on iOS 10.
I am walking the same route, wearing the same shoes and keep my iPhone in the same pocket. Have I lost these 1000 steps, or was it over-reading before?