I was wondering if there was a resolution to this, or a work around?
I am experiencing the same issue, we have a secondary app that allows users to create a cart. We then redirect them to the Shopify checkout page using the checkout api.
The problem is that the users are always anonymous from our app, and if they choose to create an account on the Shopify Checkout page, then the url is lost and they must access our app again to recreate the checkout url.
Thanks in advance.