That's an interesting thought.
If the user in this case has a Manual enrolment as the Teacher, and the duration has ended, then they could still have access to the course via some other system role or with multiple roles or multiple methods. It would be worth looking at the roles specific to this user in the course and whether they have more than one enrolment method, too. Also checking the settings in the Manual enrolment method.
If the user in this case has a Manual enrolment as the Teacher, and the duration has ended, then they could still have access to the course via some other system role or with multiple roles or multiple methods. It would be worth looking at the roles specific to this user in the course and whether they have more than one enrolment method, too. Also checking the settings in the Manual enrolment method.