title: .NET CORE 5 '''HandshakeFailure'" when making HTTPS request
body: <p>There's this request that simply won't work on c# (either RestClient or HttpClient).
  when I try connecting to the endpoint on RestSharp I get StatusCode 0, and on HttpClient I get this exception:</p>
  <blockquote>
  <p>Authentication failed because the remote party sent a TLS alert: 'HandshakeFailure'.</p>
  </blockquote>
  <p>Funny thing about that is that it works pretty fine on Postman (Yes I tried generating the code from the postman and it still didn't work).</p>
  <p>I looked on the postman and it used the TLS 1.2 certificate, then I tried this:</p>
  <blockquote>
  <p>ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;</p>
  </blockquote>
  <p>still, nothing.</p>
  <p>Checked the url, authentication, headers, http verb and everything is OK.</p>
  <p>Obs: I can only access this endpoints tru a VPN, does that ring a bell?</p>
  <p><a href="https://i.stack.imgur.com/SAqWC.png" rel="noreferrer">Checking the TLS version used by the postman</a></p>