Gradebook classic course grade issue:
Course grade display can show incorrect grade for student.
Create a site with Gradebook classic and add student(s)
You can leave the course grade options default where 90 should be a A-
Add a gradebook item worth 100 points
Grade student on that item at 90 points
View the course grade tab.
The score will show as 90, but will display a B instead of A-