The remote server returned an error: (400) Incorrect request

I have created two methods, one for authentication via certificate type A1 and A3 and another to send an xml, both of which make the request in a client apiect.

In the authentication method, I send the data from my certificate to the client and have the return of a "Set-Token" with user information, "X-CSRF-Token" CSRF and " CSRF-Expiration "with the expiration date.

Authentication method.

public void CarregaCertificado()
        {

            string destinationUrl = "https://val.portalunico.siscomex.gov.br/portal/api/autenticar";
            string requestXml = "Aqui é a string do xml";

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(destinationUrl);

            X509Certificate2 oCertificado;
            var oX509Cert = new X509Certificate2();
            var store = new X509Store("MY", StoreLocation.CurrentUser);
            store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);
            var collection = store.Certificates;

            var collection2 = collection.Find(X509FindType.FindByKeyUsage, X509KeyUsageFlags.DigitalSignature, false);
            var scollection = X509Certificate2UI.SelectFromCollection(collection2,
              "Certificado(s) Digital(is) disponível(is)", "Selecione o certificado digital para uso no aplicativo",
               X509SelectionFlag.SingleSelection);


            if (scollection.Count == 0)
            {
                var msgResultado =
                    "Nenhum certificado digital foi selecionado ou o certificado selecionado está com problemas.";
                MessageBox.Show(msgResultado, "Advertência", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
            else
            {
                oX509Cert = scollection[0];
                oCertificado = oX509Cert;
                request.ClientCertificates.Add(oCertificado);


                request.ContentType = "application/json";
                request.Headers.Add("Role-Type", "DEPOSIT");

                request.Method = "POST";

                HttpWebResponse response;
                response = (HttpWebResponse)request.GetResponse();

                string tokenResponse = string.Empty;
                string csrfTokenResponse = string.Empty;
                string csrfExpirionResponse = string.Empty;
                string keepAlive = string.Empty;
                string connection = string.Empty;
                string contentLength = string.Empty;
                string contentType = string.Empty;
                string date = string.Empty;
                string server = string.Empty;


                if (response.StatusCode == HttpStatusCode.OK)
                {
                    Stream responseStream = response.GetResponseStream();

                    tokenResponse = response.Headers["Set-Token"];
                    csrfTokenResponse = response.Headers["X-CSRF-Token"];
                    csrfExpirionResponse = response.Headers["X-CSRF-Expiration"];
                    keepAlive = response.Headers["Keep-Alive"];
                    connection = response.Headers["Connection"];
                    contentLength = response.Headers["Content-Length"];
                    contentType = response.Headers["Content-Type"];
                    date = response.Headers["Date"];
                    server = response.Headers["Server"];



                    string responseStr = new StreamReader(responseStream).ReadToEnd();

                }

               EnvioXML(requestXml, tokenResponse, csrfTokenResponse, csrfExpirionResponse);

            }
        }

Recebo os dados após autenticação sem problemas!
Depois tento enviar o xml.
Método de envio do xml.

 public void EnvioXML(string requestXml, string tokenResponse, string csrfTokenResponse, string csrfExpirionResponse)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://val.portalunico.siscomex.gov.br/cct/api/ext/carga/entrega-conteiner");
            byte[] bytes;
            bytes = System.Text.Encoding.UTF8.GetBytes(requestXml);

            request.ContentType = "application/xml";

            request.Headers.Add("Authorization", tokenResponse);

            request.Headers.Add("X-CSRF-Token", csrfTokenResponse);           

            request.ContentLength = bytes.Length;

            request.ContentLength = 1;
            request.SendChunked = true;
            request.Method = "POST";           

            Stream requestStream = request.GetRequestStream();
            requestStream.Write(bytes, 0, bytes.Length);
            requestStream.Close();

            try
            {
                using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
                {
                    if (response.StatusCode == HttpStatusCode.OK)
                    {
                        Stream responseStream1 = response.GetResponseStream();
                    }
                }
            }
            catch (WebException e)
            {

                MessageBox.Show(e.Message);
            }

        }