Did anyone figure this out? My issue is similar, but I know what the problem is exactly, I just can't figure out how to remedy it. Here's my issue:
I put all my products to have inventory managed by a 3PL.
So customers bought one of my products that is not actually managed by 3PL, but instead by me locally. So I changed the product to have inventory managed by "Shopify" (aka Me). So new orders don't have the issue where I can't print the shipping label.
But all my old orders (pre-inventory management change) are not allowing me to print shipping label, since shopify thinks that the 3PL is managing these items.
So what can I do to make my own shipping labels for these old orders? LOST! Please help!