I have a new client and we took over their site from someone else. The old maintainers used Shopify JS-Buy-SDK v0 to build their site and connect the clients site to shopify with a series Buy Now buttons. Pretty simple and it worked for a while. However, the website is now through a "no-cors" message. Specifically,
Access to fetch at 'https://<domain>.myshopify.com/api/apps/6/product_listings/<product-id>' from origin 'https://www.<client-domain>.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
The last order they received was yesterday around 4pm. What changed between now and then to make this error pop up? Also, does anyone have a quick method of fixing this that doesn't involve moving everything to v1 or v2 (that will come later).