Update for team 58SQGZ3X8Y (no.ungevil.stride, FB24811063): Sign in with Apple works for us as of 17 September, tested on device with the same TestFlight build that failed this morning. No change on our side — same App Store provisioning profile from 30 August (ACTIVE), same certificate, same binary configuration. So this looks like Apple's server-side fix reaching another team, consistent with the reports above. Closing our Feedback as resolved. Thank you to everyone who documented the signature here.

Same signature here, never worked once: team 58SQGZ3X8Y, bundle no.ungevil.stride, App ID created 2026-08-24. Native sheet authenticates, then "Sign-Up Not Completed", ASAuthorizationError 1001 with empty userInfo, nothing reaches the relying party. Entitlement verified in profile and binary, APPLE_ID_AUTH / PRIMARY_APP_CONSENT read back from the ASC API, same Apple ID registers fine in other apps. Filed FB24811063 and Developer Support case 102965715927. If anyone at Apple can look at the registration record for this client ID, we would be grateful.