Scala implicit declaration never used week warning

After updating to 2016.3.2  a get week warning Declaration is never used.

This is Scala, PlayFramework an it's quite common to use this kind of syntax, before this version this didnt show

def list = IsAuthenticated { user => implicit request => //Week warning !

Trait Definition: 
def IsAuthenticated(f: => User => Request[AnyContent] => Result) = Security.Authenticated(username , onUnauthorized) { username =>

If i change implicit request to implicit _ (default autocorrection action) trait is not satisfied !