BindablePicker control from Xlabs.Forms v2.0 cannot see in Android App

Hi, I am trying to use BindablePicker control from Xlabs.Forms v2.0 (download from NuGet package).
I could not see it visually appearing in Android app. Could anyone share ideas or locate any missing settings to use it correctly?
Contentpage has controls namespace in Xaml file as below:

Then setting its itemsource in Xaml.cs file:
this.securityquestion1.ItemsSource = RegisterViewModel.Questions;

Stepping through code, itemsource is set sucessfully but could not see picker at all in App.
Am I missing something to render this control?