FSSO and Windows 10

I'm seeing this issue more and more, especially on PC that are shared.  Maybe someone has found a fix for this. 

A user walks away from a windows 10 machine and logs out.  Another user may not log back into this machine for 20-30 minutes, but when they do they show up as a 'guest' user in the FSSO inthe 'FSSO logins' on the fortigate and do not appear in the FSSO on the DC.  Only after an immediate log out and log in do they register properly.  I have confirmed this only happens if the PC sits at the login for more than a few minutes and only to windows 10.  I believe what is happening is that windows 10 is trying to hit the internet while not logged and registering itself in the fortigate as a non-authenticated (domain) user.  Anyone else having these problems? 

The environment is a mix of windows 7 and windows 10.