Why does this happen?
This may happen when:
Creating a new page for the product in your webstore
Connecting an additional webstore
If orders come in against the new item, but the inventory is associated with the original item, this can cause orders to be held. There are two solutions to prevent this.
SKUs are unique
You can turn on an automatic merge on the duplicate skus page. Newly-detected SKUs will be merged after a delay of your choosing. The delay gives you the opportunity to clone products in your shopping cart, and then update to the correct SKU if the product is different.
Merging two items will combine their history, as if they were always one item. While you will see a line item in the item history "Merged duplicate SKUs", the item quantity balance will have been rewritten, so it will look like no change was made in quantity.
Note: If auto-merge is enabled but your SKUs are not unique, products will ship incorrectly. Whiplash cannot be held liable for mis-ships that occur from incorrect SKU merging.
All scancodes and scancode aliases are combined on the resulting merged Item.
SKU's cannot be merged unless they are identical in every way. A slight variation can cause an incorrect/inaccurate merge. If an existing item is being updated, a new variant for the SKU should always be created. Merging SKUs will not automatically update old SKU's to reflect the new product.
When auto-merge is enabled, the app merges duplicate SKUs into the newest variant.
Subscription services, like ReCharge, create new Variants that cannot be matched in our system. When auto-merge is enabled, these new variants can cause an inaccurate or unexpected merge.
Shopify Item Duplication
While creating items in Shopify, avoid creating products and variants by duplicating products and variants. It's easy to leave the same SKU or barcode and cause confusion when the new items are synced to Whiplash. If Shopify barcodes are set to sync with Whiplash, these can be added as alternate scancodes when the product is first duplicated. Scancodes can be disabled, but since Shopify doesn't prevent duplicate barcodes, this should be avoided.