Since last update the admin interface on the course front end has been changed.
on the tab "course submission" i was once allowed to check quizzes and assignment submitted or pending from each user.
Now on pending quizzes (even if i know that the quiz has been done and not yet evaluated) i see nothing... like this test was deleted.
Unable to replicate the issue .
Please check if the quiz is connected to the correct course and also auto evaluate results are disabled .
refer :
http://prntscr.com/a29bly
If still issue persists then please share the url of the quiz and admin credentials to check this at your end .