We recently had many problems with students taking a webwork exam (gateway/quiz) hitting the Preview button and finding their answers had disappeared. Could this be due to a dropped connection? Many students in the dorms are sharing the same wifi router, so it would not be surprising if connections were often dropped.
This experience has been so disconcerting that some are talking about switching to Edfinity, because presumably they have a modern web interface that records answers as they are entered.