You may find the following error message there:

Object
1234:Array[1]
0:Object
code:"100013 - EAN_MUST_BE_UNIQUE"
title:"This EAN is already used under another active SKU. Deactivate this SKU to be able to reuse the EAN."
path:"/products"
jsonPath:"$.productVariations[?(@.sku==\"1234\")].ean"
Trigger:"cli: artisan otto:item:report:result"

This indicates that the same EAN has been assigned multiple times on the marketplace. Therefore, you should search for the EAN of this variant in the error message (here: 1234) in PlentyONE and, if necessary, adjust your EANs.
Assigning barcodes multiple times is generally not recommended.