My team has a third-party app which creates product listings on behalf of merchants.
I verified that all of the variants we manage for our merchants have their ProductVariantInventoryPolicy set to “DENY”. But, customers are still able to checkout those products when their inventory stock is zero and negative. This never used to be an issue, and has only come up for the first time today.
Are there any other fields that we must set in order to prevent customers from creating checkouts for variants that are out of stock? Is it possible that the merchant changed some setting which overrides the ProductVariantInventoryPolicy?