If you're using Windows OS, then Pulse Client idle session timeout will not work due to NBNS and LLMNR traffic which gets sent out constantly through the virtual interface and reachs the VPN server, which makes the VPN server to think that there is actual data flowing through the tunnel, thereby resets the idle timer. However, the maximum session timeout should be unaffected by the former if the "Reconnect at session timeout" is disabled on the pulse connection settings.
There are several methods available on the Internet on how to disable NBNS and LLMNR traffic on Windows OS.
