Hi Apple team, For our iPhone app (App Store build), a small subset of devices report DCAppAttestService.isSupported == false, preventing App Attest from being enabled. Approx. impact: 0.23% (352/153,791) iOS observed: Broadly 15.x–18.7 (also saw a few anomalous entries ios/26.0, likely client logging noise) Device models: Multiple generations (iPhone8–iPhone17); a few iPad7 entries present although the app targets iPhone Questions In iPhone main app context, what conditions can make isSupported return false on iOS 14+? Are there known device/iOS cases where temporary false can occur (SEP/TrustChain related)? Any recommended remediation (e.g., DFU restore)? Could you share logging guidance (Console.app subsystem/keywords) to investigate such cases? What fallback policy do you recommend when isSupported == false (e.g., SE-backed signature + DeviceCheck + risk rules), and any limitations? We can provide sysdiagnose/Console logs and more case details upon request. Thank you, —