This may sound like a ridiculous question but has anyone had an issue where you knew you had graded a section or an assignment and when you went back later, now of the grades were there?  I know that sound crazy but it has happened to me at least once a quarter.  I started keeping track and mark down the assignments I graded and then a few days later, I find I have to grade that assignment again.  I've been teaching in Canvas for some years now so it isn't that I don't understand.  I just wonder if anyone else has had this issue.

Thank you in advance.