The value for a maximum grade when creating or editing a grade category in the gradebook setup is not saved.

Steps to reproduce:

1. Login as admin.
2. Go to Site administration > Grades > Grade category settings
   1. Select 'Mean of grades' for 'Aggregation'.
   2. Make sure that 'Mean of grades' is selected in Available aggregation types.
   3. Save changes.
3. Create a course.
4. Go to Grades > Gradebook setup.
5. From the Add dropdown menu, click on Add category.
6. In the Add category modal make sure that Mean of grades is selected for Aggregation, set the maximum grade to 10 and then save.
   • Notice that the newly created category has the default 100 for maximum grade instead of 10.

If the advanced form is used to create/edit a grade category the maximum grade is properly set.