This has happened to me a few times too. I finally concluded that by logging out from my FB account would reset my consecutive days back to day one. I log out and log back in with my FB account from time to time trying to force sync the progress and stickers count across platforms. Not sure if the reset is a bug or is by design. May be the Superstars or @QueenMia can comment.
As pointed out by @mysticalmysty, resetting the day count doesn't have a huge impact on the daily reward. Worst case is that you may get a small box instead of a large one. What we may lose is the bragging right of saying how many days (350+?) we have played consecutively. LOL