Duplicating items

I am having a problem duplicating items using the same item code. So here is how I can replicate the problem.
Edit an existing item and rename item code. Save and Duplicate item. Now in the duplicated item, I enter the original item code and save. Once the item is saved, I can no longer edit the item. Clicking on the item in the list does not bring me to the item edit window. I suspect some error is occurring on the server. This is installed on my own server and not running in the cloud.

Perhaps there is an easier way to do what I am trying to accomplish. Currently all my items have “Maintain Stock” checked. I no longer want to track inventory so I would like to uncheck this. Because I can’t change an existing item, I was going to go through and duplicate all my existing items and uncheck “Maintain Stock” and then re-assign the original item code to the newly created item.

Not sure if this is permissible as the transactions like orders, invoices etc would still carry the original item code. Have you checked after rename to see if these change?

I assume that orders/invoices etc are referencing the ID and not the item code. When I rename the item code, I do not see the invoice updating to reflect the new item code.