Help with core_enrol_get_users_courses

Hi all,

We are running Moodle version 353 with PHP 7.2, We are trying to use the following web service:

core_enrol_get_users_courses

Although we know that there are users enrolled in the course, it is returning null when we running it.

Ex:

https://mysite.com/moodle/webservice/rest/server.php?wstoken=ebe0f1a0f622cf88219f39bb7f2867b3&wsfunction=core_enrol_get_users_courses&moodlewsrestformat=json&userid=402646

Any idea on what might be happening?

Thanks for your help,

Carlos