When grade items in the Grades area of a D2L course are linked to a tool (e.g., Submissions, Quizzes, and Discussions), the sync only works in one direction. Grades can be sent from a tool to the Grades area, but not the reverse.
If you enter and publish grades (or grades are automatically calculated and published) within a tool, and the tool is linked to a grade item, the grades will be sent to the Grades area of the course. The grades display within the tool and within the Grades area of D2L.
If you enter grades from the Grades area of the course, and the grade item is linked to a tool, the grades are not sent to the tool. The grades are only visible in the Grades area of D2L.
Since grades entered manually in the Grades area will not be sent to the tool, grades entered manually in the Grades area will not override any grades displayed within a tool. For example, if you provide a score for a Submission folder assignment in the Submissions area of the course, and later change that score in the Grades area of the course, the new score is not sent to the Submission folder; students will still see their “old” score from the Submissions area unless that score is also updated.
For more information on using the Grades area of D2L, please see our D2L Grades guide.