OnNewEvent Not called for an Xamarin.Forms.Platform.Android.FormsApplicationActivity

I am developing an Xamarin.Forms.Shared Project for android to read data from NFC Tags.
when I deploy & test it in the device, the OnNewEvent is Not at all called **when tapped with a NFC Tag .
I have also set the LaunchMode to 'SingleTop'. Just to wanted to know am I missing any other settings/Configuration entries.