ExecuteActionOnReturn=true Not firing

Hi.

 I have a RadTextBox defined like this:

<telerikPrimitives:RadTextBox x:Name="SearchWord"
     FontSize="18.667"
     TextWrapping="NoWrap"
     Watermark="Search Word"
     VerticalContentAlignment="Stretch"
     HorizontalContentAlignment="Stretch"
     Padding="12,2,2,2"
     ActionButtonVisibility="Visible"
     VerticalAlignment="Center"
     Height="80"
     ActionButtonTap="SearchWord_ActionButtonTap"
     InputScope="Search"
     ExecuteActionOnReturn="True" />

private async void SearchWord_ActionButtonTap( object sender, EventArgs e )
    {
    await SearchTheWeb();
    }

I was expecting the SearchWord_ActionButtonTap to fire when pressing the Enter (right arrow key)?

However this doesn't happen. What am I missing here?

Thanks,
Eitan