Was working with a teacher today who had entered numbers in terms in on assignments and yet had all her assignment types set to use a letter grade scale (attachment 1). We were able to confirm in our live mirror that 24hrs. ago that the Gradebook assignment types were not configured and that numeric grades were entered on all assignments ... so how did this happen?
After testing this with the help of support, we completed the steps below to create this issue:
The only workaround for this is to remove the 'Add to Gradebook' checkbox on any configured assignments with grades. Once all graded assignments are removed, it's then necessary to complete the 'Marking Period' and 'Year' calculation switch as before to remove the applied letter grade scale. Once that's done you can then add assignments back to the gradebook and cause the previously entered numbers to appear once again.
This process becomes very tedious when you have many assignments configured for the gradebook.
Long story short, the system should not allow teachers to unintentionally set their gradebooks in the way described to use a letter grade scale for assignment types when numeric grades are already entered for those assignment types.