I've been using Shopify Lite to create storefront websites on my own server and then link the user to permalink-carts checkouts to continue with payment.
But today, I found a problem: I added a new product to my store with the same exact configuration than my older products but the permalink checkout marks it as "Sold Out", no matter if I put the item as "Continue Selling While Out of Stock", or if put 10000 stock quantities.
Works - https://lilys-kitchen-heart-of-the-home.myshopify.com/cart/52187225028:1
Does not work: https://lilys-kitchen-heart-of-the-home.myshopify.com/cart/31235099197555:1
The only difference between these two products is that the one that doesn't work was created today.
I can't spot a misconfiguration on the products nor variants. I have tried with products with variants, and with no variants. It's only happening to my newly created products, as you can see in links from above.
I literally put 2 URLs. One works, the other does not.