When pushing Symantec to clients Microsoft Forefront Doesn't Uninstall

Hello All,

     We are doing a deployment of Symantec Endpoint Protection 12.1.6.  We are trying a test deployment to a small group from the SEPM.  I created a new Client Install Settings that is the same as the default but I enabled the Automatically Uninstall Exisiting Security Software option.  I then tried to do a push selecting these new settings.  Symantec does get installed but Forefront isn't removed and is still running on the system.  Am I missing a step?  Any help is appreciated.