RemoveGroupAdmins and RemoveGroupMember

I am trying to remove user (System Admin) from all the groups he is part of by using "Remove Group Members" and "Remove Group Admins" in a process and running it as MNI one for each group but still the user was not removed from any group at all.
I made the PM lane as Run as whoever designed this process model and I am also a sys Admin but still the Smart service is not working.
Am I missing anything here?