you may experience a product issue here. The issue you describe has dependencies to some payloads of config profiles (restrictions, as far as I remember...). This was fixed with 9.96. Which version of the JSS are you running?

@m.entholzner is right...older pre-9.9x builds had a pesky issue that inserted some superfluous payloads that had 30 minute logout functionality into it. 9.96 has hit that one hard....make sure you look at the profiles on your Mac that is doing that itself. Look for extra loginwindow or login items payloads that you didn't want...that profile is what is causing this. Updating your JSS should fix it.

I use JAMF's disableAutoLogout.sh script being called at each check-in. Perhaps that's overkill but it works for my Mac labs. I defined a policy called Disable Auto-Logout, scoped it to hit all our lab computers and call it on 'Recurring Check-in'. The script itself is posted somewhere here but I can reproduce it here if you can't find it. My Mac labs are a mix of Mavericks, Yosemite and El Capitan.

Another script on each Mac forces a reboot early each morning.

Cheers...

@m.entholzner I'm running version JSS 9.96.1472575603.c

I don't have any restriction config profiles set up. Looking at my Login Window options, I see it checked there. I'm assuming that is an option recently added, as it was not there before.

I have checked my notes and found that whether Security & Privacy and / or FV2 Redirect profiles are the problematic ones. When I had those issues, the Jamf buddies recommended me to re-send profiles that contain one of that payloads. This is what I recommend to you now too :)