Resolved! The issue had to do with the Vercel Commerce starter. It was storing and retrieving the Storefront-API created checkout URL in cookies using some characters that can be unsafe in cookies, notably, `=`. This caused the retrieval of the check...

Hey Shopify team, I'm working on a Partner development store to demonstrate a headless checkout using the Vercel Commerce starter (https://github.com/vercel/commerce) and am running into an issue that I can't proceed to checkout. I see that Partner d...