Submitted title or price differs so much from the existing catalog item that Walmart's deep-matching engine flags it. Suggests wrong UPC or wrong product attached to the GTIN.
Walmart Seller Center uses identifiers (GTIN, MPN, brand, SKU) to match catalog records. Issues come from invalid format (non-numeric in a GTIN field), brand-GTIN mismatches in GS1's database, duplicate IDs across SKUs, or missing required identifiers for the category.