I just ran a quick test and the form was showing in the bindings panel. here are the steps that i took:
1. create a form with form builder
2. apply UE on the same page and click the DW edit button
Are you applying UE to the same page as the form, if not you might need to add the form to the page by going to the bindings Panel and click the + and then select Form Data and select the page that contains the form.