Daily goal and summer time
So, I guess I noticed a bug in the system. Some time ago I bought Streak Freeze, and it showed as "equipped" until yesterday. I don't know if it is connected, but yesterday I reached 7/7 day in Double or Nothing, and I thought that Streak Freeze disappeared at the same time I got my 10 lingots. Today I checked once more, Streak Freeze still missing, but experience chart appear to be wrong: I 100% remember, that I haven't missed a day, and on Friday "Streak Freeze" was still equipped. Yesterday chart showed, that I have at least 3xp per day. I also remember that yesterday I got only 3xp, but now chart shows 11xp for yesterday, and 0px for Thursday. I believe it is connected to summer time, because several days I reached my daily goal after 11pm, so maybe now it's considered as next day's xp. I already wrote to support yesterday, when my charts were correct, but Streak Freeze was already missing, and I expect to get 10 lingots back :)
I have noticed that the week starts on Sunday afternoon way before midnight so I have to have my xp before then, but the other days end at midnight and I have to be careful on the Monthly reset day and yearly reset day. I hope you get your lingots back. The clock is set to the time zone of the location where you first set up your account.
I have learned to always keep a streak freeze purchased, pay attention to the "hours left" on my home page (that tells me when my day ends so I have to get my goal before then), and to make sure I see a green check mark beside my streak and number at the top of the page before I quit for the day.