Thank you for your question. Although the UPC is set to "Does Not Apply" on eBay then the eBay listing configurator for this item has "UPC" in the specifications column so the UPC is picked up from the item due to the configurators setup. When eBay receives that information then they are more than happy to display it regardless of the settings.
If you wish to get this removed then the configurator should be edited so that specification would not contain "UPC" so that Linnworks would not send it out to the channel.
Documentation on editing eBay configurator specifications: http://www.linnworks.com/support/listing-management/listing-via-my-inventory/ebay/configurator/edit-ebay-configurator/ebay-configurator-specifications
If you have more questions on this or require further assistance then I'd advise opening a ticket since the forums are visible to everyone and there could potentially be sensitive data that should not be publicly available. When opening the ticket you can refer to this topic so that the ticket would be assigned to me.
Hope this helps.
With Best Regards,
Linnworks Technical Support
Please review my attachment
I have uploaded all product information and then listed to eBay.
However, inside of the product page on eBay shows that UPC is Does Not Apply.
Under the Item Specific, there is UPC that I have uploaded via Linnworks.
why does this happen?
Is that a kind of error by Linnworks mapping issue?