Some of students reported to their instructors and Canvas Support that they can't view grades from completed courses. If you are one of them, this information will guide you through the steps of accessing the content and grades of the courses from past enrollments (concluded courses).
Unless your instructor chose to restrict students from viewing the concluded courses after a specific date, you should be able to access the course in Read-Only Mode and view the course content and grades after the course was ended.
Concluded courses don't show up on your Dashboard anymore, but you can access them from Global Navigation Bar (the yellow bar on the left side of the screen) by clicking Courses, then All Courses. Locate the course link on the Past Enrollment list and click it.
See detailed instructions "How do I view my grades in a concluded course?" by clicking the link: https://community.canvaslms.com/docs/DOC-10494