Host name problems in WCF service metadata

ServiceConfiguration.xml

<system.serviceModel>
  <services>
    <service name="Example.ProblemService" behaviorConfiguration="CustomBehavior">
      <endpoint contract="Example.IProblemService" binding="wsHttpBinding" bindingConfiguration="ssl" />
      <endpoint contract="IMetadataExchange" binding="mexHttpBinding" address="mex"/>
    </service>
  </services>

  <bindings>
    <wshttpbinding>
      <binding name="ssl">
        <security mode="Transport">
          <transport clientCredentialType="None"/>
        </security>
      </binding>
    </wsHttpBinding>
  </bindings>

  <behaviors>
    <servicebehaviors>
      <behavior name="CustomBehavior">
        <servicemetadata httpGetEnabled="true" />
      </behavior>
    </serviceBehaviors>
  </behaviors>
</system.serviceModel>