Kushan,
The documentation is correct. You can actually add anyone enroled in the course to groups. Student, Non-editing teacher, or Teacher.
So, you need to make sure what you are calling "teachers" are actually enroled in the course. It will not work for roles that are not enroled, even if they have access to the course, such as the Manager role has.
The documentation is correct. You can actually add anyone enroled in the course to groups. Student, Non-editing teacher, or Teacher.
So, you need to make sure what you are calling "teachers" are actually enroled in the course. It will not work for roles that are not enroled, even if they have access to the course, such as the Manager role has.