We have encountered an issue reported by one of our users involving the Local Authentication framework. In our biometric authentication flow, we first check biometric availability using: let context = LAContext() var error: NSError? let canEvaluate = context.canEvaluatePolicy( .deviceOwnerAuthenticationWithBiometrics, error: &error ) For this particular user, canEvaluatePolicy repeatedly returned false with the error LAError.biometryNotAvailable (observed 7 times in our logs). What makes this unexpected is that: The user had Face ID configured and actively using it on the device. The user reported that they had not changed their Face ID enrollment. The user reported that they had not changed their device passcode. We are not aware of any MDM restrictions applied to the device. The issue appears to have been transient, as it was reported only for this user. We are trying to better understand under what conditions iOS may return LAError.biometryNotAvailable even when Face ID is configured on the device. Some questions we have: Are there known scenarios where Face ID is enrolled but canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics) can temporarily return LAError.biometryNotAvailable? Can iOS return this error during transient system states (e.g., Face ID subsystem restart, device startup, system update, thermal conditions, etc.)? Is there any recommended diagnostic information we should collect to help identify the root cause when this occurs in production? Environment: iOS version: 26.4.2 Device model: iPhone 14 Pro Max LocalAuthentication framework Face ID authentication Any insights into possible causes of this behavior would be appreciated.