Hi SiggyVE ,
I'm sorry. We didn't understand your problem correctly. We thought you were talking about duplicate barcodes between inventories of the same product. That's why we couldn't reproduce your issue.
Barcodes are unique and can't be repeated in various products. If ATUM let you duplicate them in the past, it was an error that we fixed.
However, if you want to allow duplicating barcodes between products, you can use the 'atum/model/product/barcode_found' filter to customize the behaviour.
Best Regards,
José Andrés