Can not edit item when create exchange order

Steps to reproduce

1. Precondition: Having a completed order

2. Create return for above order successfully

3. Go to return tab then create exchange order

4. Add item to exchange order successfully

5. Edit the added item above then click "Save"

=> Observed: Can not save the change, the edit line item dialog still displayed. And seem that redundant option "Charge customer for changes in shipment's shipping rate" (see attached image)

=> Expected: Can edit and save the change line item when create exchange order.

Note: This also happen on Commerce8.4-pre 339