My imported assignments that are copied from last year's canvas are giving students zeros, even though I have changed the due dates.

When they sync to PowerSchool it automatically gives them a zero. I deleted the assignment through PowerSchool so students weren't seeing that zero.

We completed in class, and when the Canvas assignment tries to sync to PowerSchool it fails now. It says "Assignment not found"

What is a work around to resync this back to Canvas?