Assignments and quiz submissions

Hi Vibe themes, I"m having some issues with the assignments and quiz submissions from the instructor's point of view When a student has submitted an assignment, the instructor gets notified, but there is nothing in the submission section. Only a previous submission is there from an earlier unit and the new one does not appear. Also when the marks are given, there is no notification to the student that the instructor has replied, and the grade does not stay in the admin section. It just restarts. (I'm talking about the assignment that appears from an earlier unit). You can see in the student stats, grades for the quiz are there but nothing for the assignment introduce yourself. The only way I can actually view the new submission for "checking into a hotel"  is in the backend, and I cannot give marks there. Also when i reply after approving, the reply doesn't show up anywhere. For the quizzes: when I check quiz submission, for some reason, the answers to the quiz by the student have a comment that was made by an instructor in reply to a question in the unit. I have no idea how it got there. There is also no notification for when comments have been made or replied to.