How can we turn off notifications in ISUPPORT for all groups of users or for separate groups of user

In version OeBS 12.2.4 in ISUPPORT notifications are sent to users, when service request are appointed to group of users. In version 12.1.3 notifications aren't sent in this case. How can we turn off notifications in version 12.2.4 for all group of users and for separate group of users? We would like turn off notifications for some groups, but use notifications for separate group.