Still experiencing this issue on macOS 26 (Tahoe). We are seeing the same storefront region mismatch when testing IAP via TestFlight on macOS. Our observations: Machine-dependent: some macOS 26 machines can complete sandbox purchases, others cannot. Observed working on some 26.2 machines and failing on some 26.3 machines, though we have not confirmed OS version as the sole factor. The workaround of signing out of System Settings > Apple Account > Media & Purchases works, but it also signs out the system account, which is disruptive. The issue appeared after we submitted our build for TestFlight external testing review (public beta). Before that, with internal TestFlight testing only, this was not reported. This follows the same regression pattern others have reported: fixed in 15.2, regressed in 15.3+, and now recurring in macOS 26. Filed as FB22050500 with sysdiagnose logs.
Topic:
App Store Distribution & Marketing
SubTopic:
TestFlight
Tags: