Ensure Grading method has been set to 'Simple direct grading'.

Simple direct grading
Marking guide
Rubric

Adjust any other grade options as desired.

Grade

Grade
Some grades have already been awarded, so the grade type cannot be changed. If you wish to change the maximum grade, you must first choose whether or not to rescale existing grades.
   
Type
 
Type
None
Scale
Point
 
 
Rescale existing grades
 
Rescale existing grades
Choose
No
Yes
 
 
Maximum grade
 
Maximum grade
 

Grading method
Simple direct grading
Marking guide
Rubric
Grade category
Uncategorised
Grade to pass
Anonymous submissions
No
Hide grader identity from students
No
Yes
Use marking workflow
No
Yes

Click "Save and return to course" to confirm changes.

Set up Simple direct grading