i would like to disable authentication in users, which they do not have any permissions. the can not do or view anything. Although they can authenticate.
By any chance do you have a Default role enabled? https://docs.microfocus.com/itom/Operations_Orchestration:2019.07/SetupRoles
If you have a role set as default, every user that doesn't match with one of your mapped groups will fallback to this Default role. If that is the case, please unset the Default role.