Another lost streak
This happened to me over this past weeked, and seems possibly to have been tied to the local daylight savings time change in the US? Duolingo showed that I had missed Saturday, though I did not.
After seeing my progress had been reset to zero after I completed the following day's work, I took a day off on Monday. A one day skip out of frustration. The odd thing is that now, on the following Tuesday, I see that I have credit for that Saturday, though at the time it showed I didn't. But since I skipped Monday ... its still lost.
So, if this happens to someone else and they happen to see this, perhaps keep at it and it will auto-correct for you within a few days; hopefully you can learn from my blunder.
Still, it is aggravating to have lost the streak ... I was somewhere between 60-90 days, I believe, and maintaining the streak was a motivation that helped insure I kept at it. Now that I know that it can be lost at any time, and, if posts here are to be believed, that support is unlikely, that motivation is diminished. :/
Thanks for sharing the details of what might have caused the problem for you, Chuggy ... I'll keep that in mind if I ever think I might need to alter my device's time settings. Hopefully they get this sorted soon, and come up with a way to set your streak back to what it ought to have been.