How to reduce the slowness while fetching response using httpwebresponse?

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C#

ASP.NET

I want to reduce the slowness while fetching response using httpwebresponse with stream reader.
i am using asp.net with c# in higher framework (4.6.1) too.
I am getting a delay of around 30 seconds and overall one minute while fetching the response XML from the core using soap header. In Soap UI there is no slowness seen.
I am using the serivcemanager for which secure protocol used is TLS1.2 and ServerCertificateValidationCallback to which SSL certificates are added,

Tried reducing slowness while detecting default proxy

<system.net>
  <defaultProxy enabled="false">
    <proxy/>
    <bypasslist/>
    <module/>
  </defaultProxy>
</system.net>

What I have tried:

My sample code is as below:

  CertificateOverride oCertOverride = new CertificateOverride();
            ServicePointManager.ServerCertificateValidationCallback = oCertOverride.RemoteCertificateValidationCallback;

            ServicePointManager.Expect100Continue = true;
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;

            const SslProtocols _Tls12 = (SslProtocols)0x00000C00;
            const SecurityProtocolType Tls12 = (SecurityProtocolType)_Tls12;
            ServicePointManager.SecurityProtocol = Tls12;

           

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(AccountStatusLookUpURL);
           
            
            request.Headers.Add("SOAPAction", "https://soa.nbf.ae/ICCSAccountLookup/ICCSAccountLookup");
            request.ContentType = "text/xml; charset=\"utf-8\"";
            request.Accept = "gzip,deflate";
            request.Method = "POST";

            request.Proxy = new WebProxy();
            request.ProtocolVersion = HttpVersion.Version10;

          
            request.ClientCertificates.Add(new X509Certificate2(Common.CORE_PFXPath, Common.CORE_PFXPassword));


                
using (Stream stm = request.GetRequestStream())
            {
                using (StreamWriter stmw = new StreamWriter(stm))
                {
                    stmw.Write(oRequest);
                    LogCORE("Request Posted successfully for Account Status Lookup API for AccountNumber : " + AccountNumber + ". Request : " + oRequest, 2);
                }
            }

HttpWebResponse httpWebRes = (HttpWebResponse)request.GetResponse();
using (StreamReader responseReader = new StreamReader(httpWebRes.GetResponseStream()))
                {
                    
                    result = responseReader.ReadToEnd();
                  
                    //XmlElement root;
                    if (!string.IsNullOrEmpty(result.Trim()))
                    {

                        XmlDocument doc = new XmlDocument();
                        XDocument xdoc = new XDocument();
                        doc.LoadXml(result);

                       
                }