I am struggling with a seemingly simple B2C custom policy that is used to sign in using phone number authentication. It is failing when trying to combine the countryCode and nationalNumber in a Validation Display Control. When using app insights to diagnose, it appears nothing is getting set even though I am typing the phone number. The country code should be defaulted to the US. CombineCountryCodeAndNationalNumber is untouched from the MS supplied templates.

Technical Profile

<TechnicalProfile Id="LocalAccountSignInWithLogonPhoneNumber">
              <DisplayName>Phone Sign In</DisplayName>
              <Protocol Name="Proprietary"
                Handler="Web.TPEngine.Providers.SelfAssertedAttributeProvider, Web.TPEngine, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
              <Metadata>
                <Item Key="ContentDefinitionReferenceId">phoneSignIn</Item>
                <Item Key="ClaimsProviderSelectionDisplayType">TextLink</Item>
                <Item Key="UserMessageIfClaimsTransformationInvalidPhoneNumber">Please enter a valid phone number and country code.</Item>
              </Metadata>
              <CryptographicKeys>
                <Key Id="issuer_secret" StorageReferenceId="B2C_1A_TokenSigningKeyContainer" />
              </CryptographicKeys>
    
              <DisplayClaims>
                <DisplayClaim DisplayControlReferenceId="signInPhoneVerificationControl" />
              </DisplayClaims>
              <OutputClaims>
                <OutputClaim ClaimTypeReferenceId="objectId" />
                <OutputClaim ClaimTypeReferenceId="signInNames.phoneNumber" Required="true" />
                <OutputClaim ClaimTypeReferenceId="displayName" />
                <OutputClaim ClaimTypeReferenceId="givenName" />
                <OutputClaim ClaimTypeReferenceId="surname" />
                <OutputClaim ClaimTypeReferenceId="strongAuthenticationEmailAddress" />
                <OutputClaim ClaimTypeReferenceId="hasFullProfile" />
              </OutputClaims>
              <ValidationTechnicalProfiles>
                <ValidationTechnicalProfile
                  ReferenceId="AAD-UserDiscoveryUsingLogonPhoneNumber-FullProfile" />
              </ValidationTechnicalProfiles>
              <UseTechnicalProfileForSessionManagement ReferenceId="SM-AAD" />
            </TechnicalProfile>

Display Control

  <DisplayControl Id="signInPhoneVerificationControl" UserInterfaceControlType="VerificationControl">
    <InputClaims>
      <InputClaim ClaimTypeReferenceId="nationalNumber" />
      <InputClaim ClaimTypeReferenceId="countryCode" DefaultValue="US" />
    </InputClaims>
    <DisplayClaims>
      <DisplayClaim ClaimTypeReferenceId="nationalNumber" ControlClaimType="Phone"
        Required="true" />
      <DisplayClaim ClaimTypeReferenceId="verificationCode" ControlClaimType="VerificationCode"
        Required="true" />
    </DisplayClaims>
    <OutputClaims>
      <OutputClaim ClaimTypeReferenceId="signInNames.phoneNumber" />
    </OutputClaims>
    <Actions>
      <Action Id="SendCode">
        <ValidationClaimsExchange>
          <ValidationClaimsExchangeTechnicalProfile
            TechnicalProfileReferenceId="CombineCountryCodeAndNationalNumber" />
          <ValidationClaimsExchangeTechnicalProfile
            TechnicalProfileReferenceId="AzureMfa-SendSms" />
        </ValidationClaimsExchange>
      </Action>
      <Action Id="VerifyCode">
        <ValidationClaimsExchange>
          <ValidationClaimsExchangeTechnicalProfile
            TechnicalProfileReferenceId="CombineCountryCodeAndNationalNumber" />
          <ValidationClaimsExchangeTechnicalProfile
            TechnicalProfileReferenceId="AzureMfa-VerifySms" />
        </ValidationClaimsExchange>
      </Action>
    </Actions>
  </DisplayControl>