Bug with choosing languages
I currently do Italian and French from English.
However, I am Spanish, and would also like to practice learning French from Spanish, for which there is an option. So I tried to start that, and it reset my French streak (100+days), and even when I revert back to the French from English, it still thinks that I have not made any progress in French
Edit: it has also reset all my xp
I had a similar experience changing languages on the ipad. When I switched back to my original language, my XP were gone. When I ran the webapp and switched to my original language, all XP reappeared and it retained my position in the skill tree. Then it was also normal on the ipad.