Custom app no longer allowed to send Admin GraphQL requests

Hello, i need assistance with the following : i made a custom app that interacts with shopify backend (customer tags and metafields) through graphql requests in the browser, it was working fine. Recently when i checked back, i found out that it’s no longer working properly . In fact it only allowed the requests if they were made by the first default domain (initialstorename.myshopify.com), but for all the other domains of our store (addeddomainename.myshopify.com for example), it now throws CORS errors, which is a huge problem since we want to move away from ‘myshopify.com’ url for our website launch. Thanks in advance