To forcibly sign out a single user, you should select the check box next to that user's login name, then select Delete Session.
If you select Delete All Sessions, all users are forcibly signed out and are unable to sign in again until Enable All Users is selected.
Selecting Disable All Users prevents users from signing in and starting a new session, but does not forcibly sign out any users that already have an existing session.
Selecting Refresh Roles re-evaluates authentication policies, role-mapping rules, and resource policies for all existing user sessions.