My organization has a custom role that was made based off of the Manager role. However all of a sudden it started being visible to the students/on the participant list. What is the name of the permission to restrict this role so that it's no longer visible?
Is it possible that your custom role has been given some teacher capabilities, or perhaps users have been assigned the role of teacher in the category context, or somehow enrolled themselves in courses?
As far as I know, the only capability related to the participants list is moodle/course:view, which allows a user to view a course without being enrolled in it, and which is allowed for the default role of manager.
Previously on this copied role enrol/category:synchronised was enabled, however the users in this role assigned at the category level were not appearing in the participant list. Now these users are appearing in the participant list, and the person who previously managed the moodle instance is saying that something must have changed, but I haven't been able to identify what.