new.js.erb NOT executed after upgrading to Rails 4.2

Here is the ajax call responding to change of name field:

$(function (){
    $(document).on('change', "[id^='order_order_items_attributes'][id$='_name']", function (){
    $.get(window.location, $('form').serialize(), null);
    return false;
  });
});

After upgrading to Rails 4.2 from 3.2, the new.js.erb is not executed anymore after the name change. In debug, the $(function(){...}) is executed as normal but the new.js.erb is not. What's missing in our upgrade? Thanks.