Image 9 patch image not working

Hi all,

I'm trying to use 9 patch images in a Xamarin.Forms project generated using the Android tool. But I'm not able to make them work as the Image control is not expanding them by default. I'm having this issue for all my Image control and with the ImageButton of XLabs

This is my Image control in Xmal:

Image Source="bottombar.png" Grid.Row="2" Grid.Column="0" VerticalOptions="EndAndExpand"

I have a corresponding bottombar.9.png image for the drawable-xx folder, but the image is not being expanded.

What am I missing?

Thanks in advance