Today I lost about 2 hours of study progress in AnkiMobile on iPhone. What I believe happened was that I was in a deck studying for 2 hours straight, switch to another app, and when I switched back all the study progress was lost. My suspicion is that the other apps used too much memory and Anki got reset. I have not been able to reliably reproduce this issue yet. This probably has happened before since sometimes I’ll be doing Anki while navigating for the driver with Google Maps running, I will switch apps and back then see cards that I thought I’ve already done. Interestingly the backup did not save my progress either. The time stamp for the backup was about 10 minutes before I switched back to Anki and realized the progress was lost, when I restored the backup, it was a the same state as the lost progress, about 2 hours before I started this study session. My other suspicion is that I never exited study mode to view the deck and somehow that didn’t save the progress.
AnkiMobile saves every change to storage immediately, so I’m struggling to come up with ideas for how this could happen. The only way your collection should be able to revert to a previous state is if you sync or import a colpkg file. I assume you did not do either of those things? If you check your statistics, do you see any reviews done during those 2 hours?
I did not sync or import when this happened. I couldn’t check the statistics for this instance since I’ve studied too many card since then.
However, this happened again a few days ago where I am almost certain I lost the progress on about 10 cards. I did about 15 cards that day then took a break for a couple hours, when I came back there was only 5 cards that had progress. When I went to check statistics, it said only 5 cards was studied that day. I searched rated:0 and only found the few cards. I continued studying, and those cards where I’m almost 100% certain I’ve studied earlier that day came up again, I went to view info on those cards and they were not marked as studied at all.
I’m wondering if it is possible that my deck or iOS app is having issues. The app is up to date but I have seen underflow error on the card count just this past month.
Thanks, I got your message. Your collection has quite a few sibling cards (eg, multiple cloze cards that all correspond to the same note), which may (at least partly) explain what you’re seeing:
the card count on the deck list will not match the number of cards you actually are presented with when burying is enabled.
when a sibling pops up as new, it can sometimes be accidentally confused with a different sibling of the same note. The next time a card pops up as new that you don’t think should, please search for it in the browse screen, and check the review history of the sibling cards so if any of them have been reviewed either.