I’m using a Fitbit Charge HR again and it has SEVERAL ISSUES.
Notably, on 12.3.17 I was able to confirm that it reset my calories for the day, presumably at midnight, from where they ended at 1206 when I plugged it into my computer and displayed 247 calories burned when I put it on at 3:10am before a workout. Those 247 were phantom calories.

The Stairs/Floors didn’t increase but I know they are not accurate either.

and I think it also had me at .01 miles and I don’t know if that is how far it is from my computer to my workout room about 40 feet away or not.

I hope the Fitbit counts the calories right when I workout. I log the start calories and end calories and do the math. It seems reasonable but I am going to replace the Fitbit with an AppleWatch I expect. Alas.