In-App Purchase works in TestFlight but fails during App Review (Apple can't complete purchase)

Hello,

I have an issue with In-App Purchases during App Review.

In TestFlight and Sandbox, everything works correctly:

• Products are loaded
• Subscriptions are visible
• Purchase completes successfully

However, Apple reports that the purchase fails during review.

My subscriptions are:

• Created and active in App Store Connect
• Attached to the app version
• Paid Apps Agreement accepted

I also added all required information (price, duration, EULA, privacy policy).

Why would purchases work in TestFlight but fail during App Review?

Thank you for your help.