Shopify has an order routing system that will assign orders to a location with the expectation you ship from that same warehouse. SKULabs allows you to link your warehouses to Shopify locations.
When you ship an order from a warehouse, SKULabs will tell Shopify which warehouse you shipped from. When the warehouse you ship from is not the same warehouse Shopify assigned the sale to, Shopify will shortsightedly restore inventory to the original Shopify Location then deduct inventory from the actual location it was shipped from.
How does SKULabs correct for this?
When this happens SKULabs is not immediately aware but our "re-push stale stock" feature will overwrite the change within a reasonable amount of time but not an amount of time you would want for high-demand or flash-sale products.
There are improvements in the works to improve this process by automatically updating inventory for all locations in Shopify when a SKU changes inventory on SKULabs. Contact support to be added to the notify list for projects 2034 & 1478.
How can I fix the source of the problem within Shopify?
We recommend you reconfigure your order routing within Shopify to assign your online orders to the correct Shopify location that is linked to the warehouse you normally ship from in SKULabs. Contact Shopify support for details.