This continues to be an issue for us on a weekly basis. Like many others here, we store inventory offsite and are able to combine items before shipping, but it is important for us to actually know where everything is. We charge a flat rate of $19.99 shipping on most items, but if someone orders products from two locations, they are charged $39.98 instead.
Based on what others have said, ShipEasy used to provide a workaround to this, but when I reached out to them it seems like it no longer works because of a Shopify API update in June that changes how they can see orders in the cart (it doesn’t distinguish one order from two locations from two unique orders), so any apps can only generate rates based on them being independent orders. I also reached out to Advanced Shipping Rules & Intuitive Shipping, which were recommended as possible solutions, but they are facing the same issues (and in some cases have stopped looking for workarounds).
So basically we are at the point where there are no possible workarounds, other than removing our inventory locations and pretending that everything is under one roof (not feasible for us). Shopify’s stance on the double charge is that it is “expected behaviour for orders with multiple fulfillment locations to be split up, even if the items are in the same profile but have multiple locations”, which is fair enough for it to be the default, but to not be able to do the alternative is very frustrating.
Has anyone found a solution that works since the June API update?