Consuming Web Reference C#

Question

I’d like a little help from you

I added the Service via Web Reference

NFSeBeloHorizonteMG.NfseWSService ws1 = new NFSeBeloHorizonteMG.NfseWSService();

ws1.Url = hostWS;

X509Certificate certificado = cert.BuscaNroSerie(noSerieCert, false);
ws1.ClientCertificates.Add(certificado);
ws1.UseDefaultCredentials = true;

string result = ws1.ConsultarLoteRps(cabecalho, consulta);

when he arrives at Consultarloterps he gives the error

Request cancelled: Failed to create a secure channel for SSL/TLS.

I’m having this same problem in other service

is not certified because some service works normally with this certificate