Entry Cursor not appearing when set in button's clicked event handler Xamarin forms

Question

Hi,
I have an entry that's IsVisible property is set to false. Then I have a button that has a clicked event handler that sets the entry IsVisible to true and sets the focus and cursor position of the entry. The entry_focused event handler is fired, but there is no focus /cursor on the entry and no keyboard appears.

Here is the Button_Clicked event handler:

void Button_Clicked(System.Object sender, System.EventArgs e)  
    {  
        //doesn't show cursor  
        AmntEntry.IsVisible = true;  
        AmntEntry.Focus();  
        AmntEntry.CursorPosition = 2;  
    }  

Please let me know how to fix this.
Thanks