WPA2 Enterprise Timeout on Airport Extreme/Mac?

Hi all,

I've got a 2013 Airport Extreme covering a small off site office for wifi, with a few Mac clients. Currently all are set to authenticate through a RADIUS server (Mac OS X 10.8.5 server) and can authenticate without issue. However, for machines that are in the office over night (ie wifi desktop edit bays), the machines are automatically disconnecting at least once every 24 hours and needing to be manually reconnected by clicking the wifi icon in the top right and selecting the network. I've got the wifi network and password stored on the machines in system preferences (with no other wifi networks in the list), but they aren't auto reconnecting on their own. However, when the correct network is selected, they connect without issue for a day and then disconnect. Also if the machines are rebooted they do connect fine. Do the airport extremes have a wpa2 enterprise timeout setting somewhere? Or could this be something on the RADIUS server? I don't have this issue with a wpa2 personal setting.

Thanks!