Session Timeout


I have setup keycloak to work with my web application. everything is good, but if the user is idle for more than 30 mins, its redirecting to the login page.
below is the screen shot of my configurations. As per the configuration the SSO idle is 8 hours, but why the session is timing out in 30 mins. Could you please let me know where am I going wrong.

Note: Using Keycloak v 16.1.0