title: 502 bad gateway - POST from C# but works fine in fiddler
body: <p>c# code in VS, I tried either WebClient, HttpClient OR HttpWebRequest, sending a post to an url, but always get 502 bad gateway error, however, the post works fine , return 200OK in fiddler or postman</p>
  
  <p>BTW, same code works fine on another machine. guess sth wrong with my machine setting, anything I can check why?</p>