Moodle assignment is showing as "Needs Grading", but looking in the submission inbox, there are no submissions available to grade. This can be replicated on OpenLMS sites and Moodle core site "demo.moodle.net".

Steps to replicate:

1. Log into site "https://demo.moodle.net",
   2. Open the course "https://demo.moodle.net/course/view.php?id=2",
   3. Create a group and add 1 user to group,
   4. Create an assignment set for separate or visible groups and add a group restriction for the above group (do not need to submit as a group),
   5. Make a submission for a user in the group,
   6. Check submission inbox, submission inbox showing "1 Submitted, 1 Needs grading".
   7. Remove this user from the above group,
   8. Assignment showing "1 Submitted, 1 Needs grading" but there are no submissions available to grade.