Same signature here — adding our team in case it helps with the server-side fix. Team ID: CAL7UMLKNY App ID: 244F9PAT4X — com.olearis.swapown (the only App ID in this team) PLA accepted: 2026-08-26. App ID registered and Sign in with Apple enabled the same day. First TestFlight build: 2026-08-27. Still failing on a build uploaded 2026-09-03. Symptom is identical to the rest of this thread: the system sheet renders correctly with our app name and icon, the user authenticates, then the sheet shows "Sign Up Not Completed" and the framework returns ASAuthorizationError 1001 (.canceled) with empty userInfo. No credential is returned, and zero requests reach our backend — our auth database has never recorded a single Apple identity. Control that isolates it to the team, not the code: the exact same Flutter code, plugin version and device signs in successfully to our dev app com.olearis.swapown.dev, which lives under a different, long-established team (4M6W632NJ7). Same Apple ID, same phone, one works and one does not. Reproduced by two independent testers on separate devices and Apple IDs. Verified on our side before posting: APPLE_ID_AUTH enabled with APPLE_ID_AUTH_APP_CONSENT = PRIMARY_APP_CONSENT, read back from the App Store Connect API rather than the portal UI. Not grouped, no wildcard App IDs — this team contains exactly one App ID. com.apple.developer.applesignin = ["Default"] present in the signed binary that was actually uploaded, confirmed with codesign on the exported .ipa, not just in Xcode. Same value in the archive before re-signing and in the final .ipa. application-identifier = CAL7UMLKNY.com.olearis.swapown in both the binary and the App Store provisioning profile (created 2026-08-26 10:51 UTC, active, carries applesignin). Distribution certificate and profile both issued under CAL7UMLKNY; only one signing identity present at build time. Native ASAuthorizationController flow, scopes email + fullName, SHA-256 of the raw nonce sent to Apple. Nothing custom. One detail specific to us, in case it is a useful subclass rather than noise: the bundle id com.olearis.swapown previously existed as App ID XQ887KP4RF under team 4M6W632NJ7 with Sign in with Apple enabled. It was deleted there on 2026-08-26 (DELETE /v1/bundleIds returned 204) and registered under CAL7UMLKNY the same day, without an App Transfer. We first assumed this was our cause — but this thread contains plenty of affected teams with no transfer or re-registration at all, so it looks incidental. Flagging it in case the backend state differs for re-registered bundle ids. FB24649664