SOAPUI and Node.JS/Request- AccessException

I am trying to build a shipment tracking tool using the Estes Shipment Tracking Web Services which use SOAP. I talked with their web support, and they are able to create a working request using SOAPUI that receives a valid response using my credentials. It would appear that my problem is the inability to replicate the request/response in SOAPUI with node.js. Why am I not able to replicate the SOAPUI request/response in node.js?

The following is the working raw request from SOAPUI that Estes web support used:

POST https://api.estes-express.com:443/ws/estesrtshipmenttracking.base.ws.provider.soapws:EstesShipmentTracking/estesrtshipmenttracking_base_ws_provider_soapws_EstesShipmentTracking_Port HTTP/1.1
Accept-Encoding: gzip,deflate
Content-Type: text/xml;charset=UTF-8
SOAPAction: "estesrtshipmenttracking_base_ws_provider_soapws_EstesShipmentTracking_Binder_shipmentTracking"
Content-Length: 468
Host: api.estes-express.com:443
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.1.1 (java 1.5)
Authorization: Basic XXXXX

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:v1="https://api.estes-express.com/ws/tools/shipment/tracking/v1.1/">
   <soapenv:Header/>
   <soapenv:Body>
      <v1:shipmentTracking>
         <search>
            <requestID>testroger</requestID>
            <!--Optional:-->
            <pro>XXXXXX</pro>
         </search>
         <debug>N</debug>
      </v1:shipmentTracking>
   </soapenv:Body>
</soapenv:Envelope>

I've omitted the base 64 encoded Basic Auth information above, but I assure you I am using the exact same value in my request.

My request is below, using node.js. I should note that I am providing proxy information in my request, but I have verified that it works in other request functions.

function estes(obj) {

    var auth = 'Basic XXXXXXX'

    var url = 'https://api.estes-express.com:443/ws/estesrtshipmenttracking.base.ws.provider.soapws:EstesShipmentTracking/estesrtshipmenttracking_base_ws_provider_soapws_EstesShipmentTracking_Port'

    const request = require('request')
    const fs = require('fs');
    const xml = fs.readFileSync('estessample.xml', 'utf-8');

    request.post({
        uri: url,
        headers: {
            'SOAPAction': 'estesrtshipmenttracking_base_ws_provider_soapws_EstesShipmentTracking_Binder_shipmentTracking',
            'Content-Type': 'text/xml;charset=UTF-8',
            'Content-Length': xml.length,
            'Host': 'api.estes-express.com:443',
            'Authorization': auth
        },
        proxy: 'XXXXXX',
        body: xml
    }, function (error, response, body) {
        console.log(body)

        fs.writeFile("response.txt", body, (err) => {
            if (err) console.log(err);
            console.log("Successfully Written to File.");
        });
    })
}

This is the XML that I am posting to their service (estessample.xml), which is the same as what the Estes web services team was using that worked above:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:v1="https://api.estes-express.com/ws/tools/shipment/tracking/v1.1/">
   <soapenv:Header/>
   <soapenv:Body>
      <v1:shipmentTracking>
         <search>
            <requestID>testroger</requestID>
            <!--Optional:-->
            <pro>XXXXXXX</pro>
         </search>
         <debug>N</debug>
      </v1:shipmentTracking>
   </soapenv:Body>
</soapenv:Envelope>

And lastly, here is the error I am receiving in response.xml:

<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
   <soapenv:Body>
      <soapenv:Fault>
         <faultcode>soapenv:Client</faultcode>
         <faultstring>[ISS.0088.9164] Access to WSDescriptor estesrtshipmenttracking.base.ws.provider.soapws:EstesShipmentTracking denied.</faultstring>
         <faultactor>http://api.estes-express.com/tools</faultactor>
         <detail>
            <webM:exception xmlns:webM="http://www.webMethods.com/2001/10/soap/encoding">
               <webM:className>com.wm.app.b2b.server.AccessException</webM:className>
               <webM:message xml:lang="">[ISS.0088.9164] Access to WSDescriptor estesrtshipmenttracking.base.ws.provider.soapws:EstesShipmentTracking denied.</webM:message>
            </webM:exception>
         </detail>
      </soapenv:Fault>
   </soapenv:Body>
</soapenv:Envelope>

from SOAPUI and Node.JS/Request- AccessException