Heya, that definitely shouldn’t be happening! That being said it never occured to me even when having a review number as high or higher than yours. @jprspereira you deal with high amounts of reviews daily, have you noticed this problem as well?
Could you tell me what kind of device you are experiencing this problem on? And if it’s not too much hassle also check if the problem also occurs in another browser or on another device?
When a card gets answered incorrectly, it usually searches for all sibling cards in the review list, adjusts them and reshuffles the list if needed. It might be that your device can’t handle it well in terms of memory, but any modern device should be fine…
Progress should always be syncing on the background as well, I have the feeling something else is causing the crash. Could you open the console (F12) during reviews and let me know if there’s any errors showing up?
You can remove reviews by demoting the cards from the individual card pages. Demoting to 0 will delete the review, demoting to another level will also reset the SRS interval of the new level.
Thanks for reporting, and I’m very sorry for the inconvenience!