Thank you for replying! If that's the case, it is not an implementation issue but a Xcode problem, right? Have you seen such an issue posted somewhere?

I am having this exact problem. Locally I can test with .storekit file and the entire flow works great. The moment I submit the app and the status of subscriptions change to "Waiting for Review", Storekit stops fetching the subscriptions and .storekit file removes previously available subscriptions once I click "Sync". Because of this, everytime I click on "Submit for review" the flow breaks basically resulting in App rejection. And I wasn't able to explain this to the Apple reviewers. If anyone has an idea how to resolve it, it would be greatly appreciated.