Just found out about that in a meeting today. But I checked the grader report setting for the course and the config for the grader report "Show show/hide icons" is set to No and when I turn editing on I do not see the eye icon.
I don't believe the instructor enabled the setting and then hide certain students and then turned off the grader report setting. Is there another action that can have the side effect of hiding grades?
I tried suspending and unsuspending a student and that does not hide their grades...
We are using Moodle 3.1.10.