Locked grade item is not being saved because needsupdate =1

1. In a course with some activities navigate to grades->setup->categories and items.
2. Edit category settings. Set Aggregation = 'Natural'.
3. Save changes.
4. Edit an activities settings. Set Locked = checked.
5. Save changes.
6. Navigate back to grades->setup->categories and items->edit settings (for the activity in step 4).

Expected: Locked setting is checked.
Actual: Locked setting is unchecked.