Missing item_group_id in a Shopify Facebook catalog

Meta uses a product group identifier to know that separate catalog items are variants of one product. Without consistent grouping, sizes and colors can be displayed as unrelated items.

Common causes

• Variant items were imported without a shared group identifier.
• A connector changed identifiers during an update.
• Variants were created as separate Shopify products.

What to check first

1. Inspect item_group_id on several variants in Commerce Manager.
2. Confirm the variants belong to one Shopify product.
3. Check that every variant has its own item ID but shares the group value.

How to resolve it

1. Correct the product/variant structure at the source.
2. Do not give all variants the same item ID.
3. If the official connector omits grouping, verify connector support before changing Shopify data.