Site being allowed correctly but blocked when user returns

I have a filter set up to exempt a site, atrtonline.com, and it works for the student to get to the site. They work on projects in the site and when they click on return to campus they get the following block

Web Page Blocked The page you have requested has been blocked, because the URL is banned. URL: www.atrtonline.com/index.php Client IP: XXX.XXX.XXX.XXX Server IP: xxx.xxx.xxx.xxx User name: HENYJ Group name: B Students

When I look in B Students the site is exempt 

Any ideas or help would be appreciated.