Logged out of Fortinet Web Interface durring active session

Hello,

Our campus recently purchased and installed a 1200D on our network.  My IT department is new to Fortinet and thus learning how to use the device.  We are having a problem with being logged out of the web administrative interface on the idle timeout.  This is causes the admin session to be logged out regardless if the session is idle or not.  I've messed with duration of timeout with the same results, forced logged out on the interval even when I am actively using the system.  Any ideas as to what might be causing this?

Thank you,

Bryan