Hello @CarolGuthrie
Thanks for posting this in the global Canvas Community!
if you are seeing the icon that looks like a paper with a clock, it usually indicates that a submission has been received but has not been graded, a submission was graded but the grade was removed by the instructor, the assignment or quiz was resubmitted by the student, or that a submission was received for a quiz but it has not been fully graded (Manual grading required).
In my opinion, the best place to start out is in speedgrader. Speedgrader should show you more details surrounding the student and their submission. if they resubmitted after you originally graded them, you should see an option that asks you to Use the same grade for the resubmission.
Hopefully this helps! Let us know what you find out on this!
-Colton