Not able to access Canvas course

[DD4]

Hello,

I signed up for a teacher Canvas account with my  email at https://www.instructure.com/canvas/login/free-for-teacher and then created a course with me as the instructor. I invited a colleague to that course as a student. The colleague has a .edu address.

The colleague received the invitation and accepted, but can't see the course in their Canvas. They primarily use a university Canvas account. Do you know why they can't see the course I created?

Would they need to create an account on: https://www.instructure.com/canvas/login/free-for-teacher?

Something else?

Thank you,
Dave