I have this issue too, I receive the enrollment email like this:
Username :
Password : 1Admin@23
To enroll and access your course please click on the course link given below :
To access your course UCDM – test
You need to change your password after first login.
Also, when clicking the link, it always takes me to the same user dashboard, a that was created not with the clients email but with the WordPress website email, so it doesnt matters how many times I register the in the course, there is onle one user in moodle.
Hope you can helpme with this, THANKS!