Adobe wsdl Soap call only accepts one input - PHP

Hello and thanks for reading,

I am stuck as to why my ES workflow is only accepting one input from my PHP soap call.

My workflow expects two inputs, a record ID and an email address.

I setup an array, called $params, to store these values (ex. $params['recordid'] = 12345 );

When I step through the workflow to debug, I see the record ID set, but the email address input is still empty.

Would anyone have thoughts as to why this would occur? I have my PHP code pasted below for reference.

Thanks!

----

    // Addresses the time to wait for a response
    ini_set('default_socket_timeout', 180);

    // Connect to the WSDL connection above
    $client = new SoapClient( $URL, array("connection_timeout"=>20) );
       
    // Try to initiate the workflow
    try {
        $returnval = $client->invoke_Async($params);
    }  
    catch (SoapFault $exception) {
        $success = 0;
    }