As a teacher I am not able to see the attempts made by students on a particular quiz in one course, but I am in another. The page shows that no students attempted the quiz, but I know that one has. Can anyone help me understand what I am missing?
I don't think we can help without more information. What you are describing is certainly weird. You need to start looking for things that are different between the two courses, quizzes, students, etc. Once we know what differences exist, we may be able to help you diagnose which difference is causing the problem.