SKU does not match any ASIN and contains invalid value(s)

Im building in a new product and getting an error in the External product ID error.

"The SKU does not match any ASIN and contains invalid value(s) for attributes required for creation of a new ASIN"

Even when selecting UPC.

Support claims my UPC is not valid even though i have tired everything and its not working

the amazon team are not answering me and always send reminder even if i have answered them

Any recommended actions to take so we can get this product going?