Hello, our professors are experiencing several issues with the assignment grader when attempting to filter the list to show only students who need grading and the first user in the course participants list hasn't submitted an assignment...

Here is a video demonstration of the error and what we've identified [00:07:51]

There are several things to note: 

1. This happens when you choose "Grade" from an assignment page. 
2. The first time you apply a filter "Needs Grading," for instance, the page shows no users selected and you have to click the next arrow to load the next user.
3. When you exit the assignment grader and return (if the first user in the class list doesn't have a submission) the moodle page shows an error (see video link below). 
4. And then you have to select the first user from the filter.
5. Regardless of the filter, the page attempts to load the first user in the course list based on the last name. It should however, load the first user that matches the filter settings. 

Steps to replicate: 

1. create a test course with a moodle assingment
2. Enroll two test users as students
3. log in as the 2nd student in the list. 
4. submit an assignment.
5. Log out and log back in as an admin or professor
6. Navigate to assignment page. 
7. Click Grade
8. Click on the filter icon in the top-right and choose "requires grading"
9. Note that the number of filtered users shows 1 of 1 but the filtered user doesn't load and it says No Selected users at the top of the page (this is really confusing to professors).
10. Note that the userid in the URL at the top of the page matches the first user in the course (based on alphabetical last name). 
11. Exit the page...
12. Return to the assignment page and click grade
13. Note the Unfiltered User Error that appears. 
14. Note that you still see 1 of 1. 
15. Select the right arrow or the dropdown to see the first user.