I am a Shopify developer, and running into really frustrating issues when it comes to how Shopify now calculates shipping across multiple locations.
I believe they refer to this as 'Multiple Origin' shipping.
Essentially, Shopify doubles shipping across multiple locations, and 'breaks' many shipping apps intended functionality.
So - if I want to charge a 'maximum' shipping charge for orders - and set filters up on a shipping app to establish a shipping rate that sets this charge, Shopify ignores it and charges it per-location.
Rate 1: If order contains products from Vendor 1, charge $5. Rate 2: If order contains products from Vendor 2, charge $5 Rate 3. If order contains products from Vendor 1 AND Vendor 2, charge $5
For rate 3, Shopify will charge $10 by default, purely based on the fact each vendor is from a distinct Location.
This is really frustrating, and breaks the way many shipping apps are intended to be used in this context.
REALLY appreciate anyones thoughts here, and any advice on how to achieve what i'm looking for.
I would even settle for a hacky solution as this point ... just need to get it done.