Hi @einardo ,
Unfortunately what you are looking for is not possible. Once a Shopify merchant activates Multi-Origin Shipping, whenever they have products in an order that need to be shipped from different locations, a shipping or delivery fee is calculated for each item and then all the shipping fees are added together. The customer is shown only the final shipping cost at checkout (e.g. combined rates). There is no way to change this unless products are shipped from the same origin. Once a merchant enables Multi-Origin Shipping, it cannot be disabled
Some more resources here: https://help.shopify.com/en/manual/shipping/setting-up-and-managing-your-shipping/convert-to-shipping-profile