How to update Kiosk Timout
To do this login to the desktop client with the admin account.
Navigate to Home > Configure System > Policy Manager > Screen Policy > select ‘Screen Type’ as ‘Kiosk Screens’ > expand kiosk > edit ‘KioskWelcome' screen.
Select the ‘KioskSessionTimeoutInSeconds’ flag and set the value in seconds as per your requirement > Hit Save