Q: Why aren’t the grade items in the correct categories when I copy them to a new course?
A: https://d2l.custhelp.com/app/answers/detail/a_id/1390/

Issue: In the Copy Course Components tool, if you select individual grade items rather than copying ALL grade items, the grade items do not stay associated with the correct categories. (This issue exists in the current version 10.1 SP9)
Workaround: In the Copy Course Components tool, copy all grade items into the new course and then simply remove the ones you don’t want from the new course.
Note: This issue only exists for Copy Course Components. If you export selected grade items, the grade category associations are retained accurately.