So I was going through a review batch (20 or so) and something weird happened.
During the time it took me to remember an answer, the page automatically refreshed. Progress status (ie Percentage of right answers) was reset, and items I reviewed before lost track of my previous answers (meaning items that should have been marked incorrect were marked correct and up a SRS level).
This happened to me twice. I’m using Safari on MacOS Sierra.
Not sure if this was a problem on my end but wanted to share anyway to get some feedback. Will report if this keeps happening.