A few days ago I did a short 3km run and my Microsoft Band 2 was telling me I was running very slow; my first 400m seemed to take forever and I was running at a pace slightly faster than walking. Turns out my Band had reset its settings from kilometres back to miles.
Looking at the Microsoft Health app (in Settings > Preferences), I was set to be using Metric units. This looked fine, but yet my Band still showed Imperial.
There are no settings on the Band 2 directly to change to Metric, so I was a bit unsure of what I could do.
As it turns out I need to access Preferences in the Microsoft Health app, change the setting for Distance and Height to Imperial, save, then set it back to Metric and save again.
Happily the Band immediately showed me my previous results in Kilometres.
This is the first real issue I have had with my Microsoft Band, apart from needing to be out of direct sunlight to see the screen. I think this is a great piece of kit, and definitely more accurate GPS than my Garmin Forerunner 220.