Learning Group not enrolling a user in courses


I have 2 Learning Groups 1 for free users, 1 for paid users. The paid course list is larger than the free one.

When I update the _RoleCategory attribute to 'Member' it seems to correctly enrol the user in those courses.

Due to a user not paying their fees, my process involves unenrolling the user from the paid courses, then updating their _RoleCategory attribute to 'RegisteredUser' which is assigned to the free course list and should therefore enrol them in the 3 free courses.

In the Brightspace UI it clearly shows this user as a part of the free learning group, however, the user has not been enrolled in any of the free courses.

Does anyone have any advice on what might be going on here?

All my operations are being done via the API and not by uploading CSV's to the UI.