Why are some product variants missing when importing into Shopify?

When variants are missing during import, one common cause is that the product in Shopify uses a connected option (for example, Shopify’s standard "Shoe size" option). Connected options only allow values that exist in Shopify’s predefined list. Any new or custom sizes outside that list cannot be added—even if they are valid in the feed.

If the product was created earlier with a connected option, Stock Sync can update existing sizes that match by SKU but cannot add new ones that Shopify blocks. To allow all sizes to be imported, change the connected option to a regular custom option (for example, rename it to "Size"), or delete the product so that the feed can recreate it with normal options.

Updated on: 08/07/2026