Bug: Received an email "you are on a 2 day streak" yet I'm on a 26 day streak
Might have something to do with using a Streak Freeze the other day.
It might also be based on an individual language streak rather than an overall one. Especially if you've switched between Spanish and French (with a break of practising from either one).
That is most likely the case, because the apps and email notification track individual language streak, whereas right now, the website is only registering the overall streak.