Now that you’ve provided a shot of the input screen, I understand what you mean. This change and the reasoning behind it was announced in [16.3.19] Added "Code" field to inventory kits and invoice items, just a few days ago.
I guess the way to think about item names and now item codes is that they are meant as shortcuts during transaction entry, of whatever type. The real description was always meant to go into the Description field. In fact, invoice items were a relatively recent addition to the program, whereas descriptions have always been there.
In your case, it looks like you’ve been putting a code number of some type into the Description field and using the Item Name field for the description. I suspect it will be tedious to correct, but I think you should reverse all of them.