Still happening in late 2026, now on watchOS. Setup: watch-only app (no iOS companion), StoreKit 2, one non-consumable IAP in "Ready to Submit", distributed through TestFlight to an external group. A tester in Austria (Apple Watch Ultra 4, Austrian Apple Account) gets "Account Not In This Store: Your account is not valid for use in the U.S. store. You must switch to the Austrian store before purchasing." "Change Store" opens the app's page in the App Store on the watch, and retrying gives the same alert. Restarting the iPhone and the watch didn't help. With my Spanish account the purchase goes through, but Product.displayPrice shows the U.S. price ($4.99) while the system sheet charges €3.99. priceFormatStyle.currencyCode also comes back as USD. So the watch resolves the U.S. storefront for product metadata in TestFlight, whatever the account's country. The alert appears before StoreKit returns anything to the app, so there is nothing to handle on our side. Has anyone confirmed whether this also happens in production for a watchOS app, or is it TestFlight only?