I want to put products in packages and track them. I have checked Delivery Packages in Configuration in Settings, clicked the button of "put in packages" and assigned specific packages, e.g., "PACK00003", and I have also validated the shipping quantity in the WH/OUT form. Packages are successfully created, but there are nothing in the packages. There is no weight, no item names, no quantity. It is empty. 

What could have gone wrong? Thank you in advance!