Grades Disappearing from Gradebook

Community Novice

I have had students completing assignments in Canvas and syncing their grades with PowerSchool; however, when I went sync today for the end of the quarter, all the grades in all my classes have disappeared. What is going on, and how can I fix this. I know I can see the grades in gradebook history, but I would really like to not have to write down all those grades and enter them manually into PowerSchool.

Thanks for any answers.