"completed" books reset

[lorraineg57]

I don't know if I've asked here before or not but I'll ask again. The "completed" annotation under the title of my completed books has disappeared. i rarely turn the device off, just let it sleep. One night half my books were marked as completed and the next time I woke it or turned it on, all of the books were reset to unread. Since then, the few books I've finished are showing as completed but I probably have 70'ish books on it and I've likely read half of them. Some I recall just by the title or cover but the others, I have to open them and see if it opens at the beginning or end to tell if I've read it. Ideas on any way to return my "completed" status short of opening every single book and RE-completing them?