I'm part of my institution's support team for Canvas. An instructor reports that some students are unable to see comments on Quiz attempts. After one of the students helped me investigate, we traced the problem to an apparent inconsistency in navigation between Assignments and Quizzes, in student view.

For Assignments, whether I start from the Grades link in navigation or the Assignments link, it leads to a "Submission Details" view that includes the instructor's comments in the right sidebar. The URL looks like this: https://institution.instructure.com/courses/1234/assignments/12345/submissions/1234

View of an Assignment submission, with instructor comments in right sidebar

For Quizzes, when I start with the Grades link, it goes to a similarly structured "Submission Details" view that includes instructor comments. The URL is analogous:
https://institution.instructure.com/courses/1234/assignments/56789/submissions/3456

View of a Quiz attempt, showing instructor comments in right sidebar

But if I open a Quiz from the Assignments or Quizzes navigation link, it takes me instead to a Quiz "History" view that shows no instructor comments for the same attempt, nor any evidence thereof. The URL contains /quizzes/ instead of /assignments/.
https://institution.instructure.com/courses/1234/quizzes/23456/history?version=1

View of a Quiz attempt, with no instructor comments visible.

Is this behavior intended? It's confusing to our students and to me, and I wonder what purpose this "History" view serves that isn't served better by the "Submission Details" view.