按下API时无法连接到远程服务器

我面临一个非常奇怪的问题:

I am facing a very weird issue:

案例1:使用ASP.NET Web开发服务器:应用程序点击了API，一切正常.

Case 1: Using ASP.NET Web Development Server: The application hits an API, and everything works fine.

案例2:我将应用程序(MVC)托管在IIS上:当应用程序尝试访问API时，它会收到错误消息:

Case 2: I host my application (MVC) on IIS: When the application tries to hit the API, it gets the error:

无法连接到远程服务器":{连接尝试失败，因为在一段时间后被连接方未正确响应，或者由于连接的主机未能响应96.17.180.160:80而建立的连接失败"}

"Unable to connect to remote server": {"A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 96.17.180.160:80"}

代码行:

HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(api);
HttpWebResponse response = (HttpWebResponse)request.GetResponse(); // This line breaks...