We had multiple students with this problem. They would start the quiz and see a blank screen with no questions.
We logged in as the students on multiple browsers and saw the issue so it's not a browser problem.
, then students start the quiz and don't see questions displayed, then the instructor edits the quiz, but because the attempt has been started the quiz won't display the questions on the resumed attempt.
I created a test quiz myself with no questions in it, and confirmed this is what happened.
Not sure why Canvas lets instructors publish quizzes with no content in them.
The workaround fix was to give the students a second attempt and then submit the first attempt.