We are experiencing the same issue with two independent native iOS apps on an iPhone running iOS 27.0.1, using TestFlight in France.
Our annual subscription displays US$34.90 instead of €39.90, and our non-consumable purchase displays US$5.99 instead of €6.99.
Both apps displayed the correct EUR prices during local Xcode testing. In TestFlight, Apple's native purchase sheets still show the correct EUR prices, and both purchases work successfully.
We have contacted Apple Developer Support (case 103017935062).
As this issue is delaying the time-sensitive release of our educational app, could Apple confirm whether a workaround is available or whether a fix is planned?
https://developer.apple.com/forums/thread/845478
Thank you.