title: Two calls on Post request: with http 204 and 200
body: <p>I have implemented  Cors policy in dot net core application:
    In <code>Startup.cs</code> under <code>ConfigureServices</code> I have added the following cors policy</p>
  
  <pre><code>services.AddCors(options =&gt;{
                  options.AddPolicy("CorsPolicy",
                      builder =&gt; builder.AllowAnyOrigin()
                      .AllowAnyMethod()
                      .AllowAnyHeader()
                      .AllowCredentials());
              });
  </code></pre>
  
  <p>I'm facing a strange issue after adding CORS policy, on every POST call from UI there are two calls made: first calls returns with 204 and other call returns the data with 200 status code. </p>
  
  <p><a href="https://i.stack.imgur.com/SJvT0.png" rel="noreferrer"><img src="https://i.stack.imgur.com/SJvT0.png" alt="two calls on post request"></a></p>