Shipped products to Amazon only to realise those shipped have different UPC

This is our first time shipping products to Amazon for FBA. We sent a box made up of 4 different SKUs. The items have been received and 3 of the SKUs have been successfully received and are available for sale.

However, one of the SKUs says ‘Receiving’. On checking (Amazon hasn’t contacted us yet), it seems that the UPC on the products we sent is different from that listed under the product ASIN.

This product is under the brand registry and also has transparency codes affixed. It seems that when checking on https://www.barcodelookup.com/, there are two UPC codes for the same product.

What should we do in this instance?