使用XML的SOAP调用不返回任何内容（Wordpress php）

Question

I have this soap call in

page.php

$client = new SoapClient('http://myservicelink.com?WSDL', array('trace' => 1));
$parameters = array('CustomerNmb' => '*****', 'Shippingnumber'=>'3498302390484309');
$res = $client->Tracking($parameters);

But this is not returning anything. I've tried checking the xml in SOAP UI and that is working perfectly fine.

In soapUI(where it works)

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tem="http://tempuri.org/">
   <soapenv:Header/>
   <soapenv:Body>
      <tem:Sporing>
         <!--Optional:-->
         <tem:request>
            <!--Optional:-->
            <tem:Shippingnumber>3498302390484309</tem:Shippingnumber>
            <!--Optional:-->
            <tem:CustomerNmb>******</tem:CustomerNmb>
         </tem:request>
      </tem:Sporing>
   </soapenv:Body>
</soapenv:Envelope>