Hi
does your login form have a "remember me" checkbox? If this checkbox is marked true for the current user, then they are not impacted by any of the system properties surrounding timeouts for user sessions. This is important for admins to understand.
When the system property glide.ui.auto_req.extend.session is marked true, ServiceNow will take the value that the user has set for their homepage refresh time, and automatically extends the users' session by that amount. So it takes the system timeout value, and then adds that to their homepage refresh value. If no homepage refresh value exists here, then the normal system timeout values will be used.
So in your case I can imagine that the session timeout of the above message is displayed but under the hood the session was already extended by ServiceNow automatically.
Kind regards
Maik
