1. Enter a course as Teacher (or admin/manager). Make sure Student A has grades in the course.
2. Go to Participants list and suspend Student A or put in a past enrolment end date for them.  
3. Login as Student A.
4. From the User menu click Grades.
5. In the section "Courses I am taking" notice grade from the course where Student A is suspended / not current.
6. Also concerns suspended / not current Teachers and non-editing Teachers. They will see links to the course(s) where they are suspended in the "Courses I am teaching" section of the User menu > Grades page.

Leak similar to MDL-64063 and MDL-64155.

So far only tested today's master:  2018112300.00, 3.6beta+ (Build: 20181123) .

Not sure if the only component concerned here is "Navigation".