The source for course enrollment is a collection of "custom course enrollment", uploaded through the CSV file on the admin panel, and the data received from your IT team. Editing the course_enrollment.csv file on the admin panel will only affect the custom course enrollment that was previously imported through the course_enrollment.csv, not the information within the Course Enrollment SFTP Import. To manually upload custom course enrollment, please review the article, Optional (Admins): Manual Upload for Course Enrollment.
IT article: Optional Admins IT Integrations