Some teachers complain that their "My Courses" does not display all the courses they created. As an admin, how can I rectify that issue?
Your teachers may have permission to create a new course, but in order to see the course within their My Courses list, they need to be enrolled in it. The process of course creation (via System Admin) does not include automatic enrolment into that course. Simply go into the course and enrol the teacher, and they will see the course within their My Courses list.
They are able to create courses and are enrolled in them. This one teacher complained that she can only see 4 of her courses, some of which were older courses from previous semesters. Is there any limit to the display of "my courses"? If there is, then it probably is set to 4 but can be extended to more. The thing is I don't know where to check for such settings.
If you customise the My Courses Screen, make sure that the Always Show All option has been selected. See screen shot below.