My assumption would be that you have not yet logged any finds during the last two days. Can that be? In this case, if you have a streak from 28 September 2016 till 26 November 2017 (and have not logged any cache on 27 and 28 November) the statistics created on 28 November will show exactly this. For the streak of course days longer back than one year will be counted (but not for finds in the last 365 days) and days after the last find up till the day the statistics are calculated are ignored.