Due to the nature of Teams meetings and our system setup, it is possible for you to join a class meetings without actually having direct access to the class team; for example, a meeting link, a calendar entry, direct requests, etc.

While this is possible, it is not the recommended point of access for numerous reasons - one being the inability to use the chat feature in the meeting. However the fix it simple, you will need to adjust your teams account organization. To learn more on how to do this, read and follow the steps outlined in Why is my class not showing up?