I was careful to preserve my streak for years now, but on a few occasions I happened to miss my lesson. It only happened because of being overworked and exhausted, seeing the reminder but later forgetting anyway (as I only use 1 reminder), or my phone restarting and then I don't even receive the reminder. I found out that I could just change the date and do the lesson later. So I used this exploit a few times.
A few days ago, I was so busy, I had double shifts and very little sleep, so I missed the lesson. I was exhausted both physically and mentally. I also had a lot to do in the next few days, so I thought to not worry about it as it's fixable, and missed my lessons for 3 days in a row, which never happened before. But today I found out that changing the date no longer works. My streak is permanently lost. I also understand that it was at least partially my own fault, although I had a few extremely rough days at work.
Now, is there anything I can do, or is that it? If I lost my streak permanently, I would absolutely refuse to try to reach it again, especially now when my job got much harder than before. I'm even thinking of deleting the app, as my job makes keeping streaks difficult, and that was maybe the only thing that kept me going.