I managed to successfully create an account and enrol a user into the course I wanted to enrol them - hurray!
However, I also need to be able to enrol and existing user into a course, and this did not work out. I tried all the settings from the drop-down but nothing worked out.
Screenshots to illustrate what I need (and what is happening). The bottom user was the existing one, and it does not show in the Enrolments tab. It was also not enroled in the course.
Any idea how to enrol exisitng users in a particular course? Or what the issue is? I have tried all the different settings from the drop-down menu in the previous screen.