BigIP APM 12.1.3: username variable session.logon.last.username empty

I have an irule which triggers an access policy based on a condition => $EnableAPMPolicy equals 1

 when HTTP_REQUEST {
ACCESS::disable     
if { $EnableAPMPolicy equals 1 } {       
    ACCESS::enable
}

}

So by default I set ACCESS::disable in the HTTP_REQUEST. This was preventing IE from getting the username variable somehow. I added a condition which only calls ACCESS:disable if $PolicyEnabled = 0 Now IE is happy and variable is passed along.

     when HTTP_REQUEST {

if { $EnableAPMPolicy equals 0 } {       
    ACCESS::disable
}

if { $EnableAPMPolicy equals 1 } {       
    ACCESS::enable
}

}