Switching overview styles between flashcard & list views when marking known terms causes the new term to be shown in the wrong style. If you're in list mode and switch to flashcards, the replaced term shows up as a flash card & vice versa. You have to reload the page to get the replaced terms to match the current style.
When in flashcard mode, marking a term known causes the new term on the flashcard to be misaligned. Part of another term shows on the current flashcard.
However, it exposed another bug that I'll get to later this week: if you mark a term as known or hidden, then switch views, it will re^show the marked term (even though the data has been saved correctly). At the same time, the new term that got pushed into its place will disappear, although the quiz will function correctly with the expected terms in (or not in) it.