Shopify discountAutomaticAppUpdate functionId returned wrong

Topic summary

Issue reported with the Admin GraphQL mutation discountAutomaticAppUpdate: the functionId returned after creating an automatic app discount does not match the functionId sent in the request.

Developer confirms via debugging that the expected functionId is passed to GraphQL, but the response contains a totally different functionId. This behavior began yesterday and had not occurred previously.

Reference to Shopify documentation is provided for the mutation, suggesting the problem may relate to how function identifiers are handled in the response. FunctionId here refers to the identifier of the app’s function used to power the discount logic.

No explanations, workarounds, or confirmations from Shopify are included yet. The thread remains open with an unanswered question about why the returned functionId diverges from the input.

Summarized with AI on January 23. AI used: gpt-5.

https://shopify.dev/docs/api/admin-graphql/2023-04/mutations/discountAutomaticAppUpdate

Hi, since yesterday my extension is creating the discounts with the functionId(refer the link above for the documentation), I do debug before I passing the functionId to the graphql, it is the expected functionId I passed to the graphql

after the discounts successfully created, the functionId returned is totally different to the one I passed in, do anyone know why? I only faced this issue since yesterday