BiometricPrompt FACE ID authentication is not working in some device

Question

I have implemented biometrics authentication but it is working fine in my Samsung(Android 10) device but not working in one plush and MI device.

In Mi(Android 10) and one plush(Android 10) device, it shows only fingerprint prompt but not showing the option of face authentication

I have set my face id in both devices setting but It is not working. only works in Samsung device.

I have used below code

    executor = ContextCompat.getMainExecutor(this)
            biometricPrompt = BiometricPrompt(this, executor,
                    object : BiometricPrompt.AuthenticationCallback() {
                        override fun onAuthenticationError(errorCode: Int,
                                                           errString: CharSequence) {
                            super.onAuthenticationError(errorCode, errString)
                            Toast.makeText(applicationContext,
                                    "Authentication error: $errString", Toast.LENGTH_SHORT)
                                    .show()
                        }
    
                        override fun onAuthenticationSucceeded(
                                result: BiometricPrompt.AuthenticationResult) {
                            super.onAuthenticationSucceeded(result)
                            Toast.makeText(applicationContext,
                                    "Authentication succeeded!", Toast.LENGTH_SHORT)
                                    .show()
                        }
    
                        override fun onAuthenticationFailed() {
                            super.onAuthenticationFailed()
                            Toast.makeText(applicationContext, "Authentication failed",
                                    Toast.LENGTH_SHORT)
                                    .show()
                        }
                    })
    
            promptInfo = BiometricPrompt.PromptInfo.Builder()
                    .setTitle("Biometric login for my app")
                    .setSubtitle("Log in using your biometric credential")
                    .setConfirmationRequired(true).
                    setNegativeButtonText("login")
                    .build()
    
          
            val biometricLoginButton =
                    findViewById<TextView>(R.id.tvClick)
            biometricLoginButton.setOnClickListener {
                

biometricPrompt.authenticate(promptInfo)
        }

Answer 1

It looks like FaceId is recognized as a Weak type of authenticators for Android 11. If a set allowed authenticators like below it begins to work:

new BiometricPrompt.PromptInfo.Builder()
                        .setTitle(getString(R.string.mcm_fingerprint_promt_message, appName))
                        .setAllowedAuthenticators(BIOMETRIC_STRONG | DEVICE_CREDENTIAL | BIOMETRIC_WEAK)
                        .build();