When hiking with GPS tracking on my Lily always says I walk about 1.5km more than my husband's GPS ( ie Lily says we hiked 7.5km his says 6km). Thought his was wrong buy now realise it's my watch?
I have the same problem. I ran with my old watch (FitBit) and my Lily this morning and it was way off. My watch also dies very quickly and when it goes off, it doesn't sync with the steps on my phone...