We are working on your issue and will get back to you as soon as we can.
Sasha (Xafari Support)Agent
We have replicated the behavior which you described in attached file, but couldn't find a solution at the moment. Please give us additional time.
Let us know if you need further assistance.
If you like to make this form in master-detail relationship you should use RelationType=DetailsCurrentObject and order's detailview (it can be copy of exist view and you can leave only one collection on form). Use case that presents in DemoApplication can be used only for demonstration one of the representation variant. Thank you for your patience.