title: SAML Response is empty - GetExternalLoginInfoAsync is null
body: <p>I am using Okta as an identity provider and configured the metadata, url, etc in startup. The request is going to Okta server and after entering username 
  and password validate the user and response comes back. But when check in 
  fiddler the response is blank. SAMLResponse is blank. The relaystate there is a 
  hashed long string. Hence my GetExternalLoginInfoAsync is null. Any idea on this 
  issue. Also setup the firstName, LastName etc in Okta.</p>
  
  <p>Thanks</p>