Hi @WendyAdornato ...
The assignment group called "Imported Assignments" that you see on your "Assignments" page is not a requirement for you to import assignments from one course to another. When you import assignments from one course to another, Canvas sometimes puts assignments in an "Imported Assignments" assignment group just to let you know they were imported (copied) from another course. So, if the "Imported Assignments" assignment group isn't there right now, it might be re-added when you start importing assignments again.
Also, there's something else you can try...but no guarantees that it will work. There's a way to "undelete" content in your course. Check out this write-up:
Undeleting things in Canvas
I hope this helps in some way. Sing out if you have questions...thanks!
