SSSD.CONF simple authentication not working

Hi All,

I have setup LDAP with kerberos for AD users to login to hosts, all works, users are authenticated and are issued kerberos tickets. Problem is anyone with a UID can log in regardless of how I restrict the simple authentication.
access_provider = simple
simple_allow_groups = A-Team

Is there a config that over-rides the sssd.conf setup?

Thanks