[UPDATED] We are currently implementing the first stage of the fix for the free download counter. (FINALLY!) Due to this, you may see your numbers jump around a bit.
Right now, the Dashboard is combining your free downloads, and free previews of books that might never have been free, so the free previews are accounting for the higher numbers that you are seeing; and potentially making it looks like there have been free downloads of a title that has only actually been previewed by a Kobo customer.
Don't worry, we are not just giving your books away!
(ALSO: There are likely ways for you to take advantage of being able to see PREVIEWS in this way to help you understand how many customers have previewed your books - and if they are converting successfully to sales for you - a bit more info about that appears here: https://kobowritinglife.com/2017/08/09/kobo-writing-life-podcast-episode-88-five-strategies-for-using-free/)
We are working towards separating the two streams of data in a future update.
We will update you via a notification on the Dashboard when we have more information.