title: Unsupported API version with versions within URI — what's wrong?
body: <p>I have a Web API project using <strong>.net core 2.2</strong> (maybe there's the problem.)</p>
  
  <p>The routes are awaiting OAuth authorization with OpenIdDict, but that works totally fine for me. I am trying a very simple approach:</p>
  
  <p>The startup.cs just contains:</p>
  
  <pre><code>services.AddApiVersioning();
  </code></pre>
  
  <p>The API controller has three different routes for test purposes. Notice that the controller itself has no [Route()] or [ApiVersion()] annotations. </p>
  
  <pre><code>[HttpGet]
  [Authorize]
  [ApiVersion("2.0")]
  [Route("api/v{version:apiVersion}/vt")]
  public IActionResult GetVt20()
  {
      return Ok("2.0");
  }
  
  [HttpGet]
  [Authorize]
  [ApiVersion("1.0")]
  [Route("api/v{version:apiVersion}/vt")]
  public IActionResult GetVt10()
  {
      return Ok("1.0");
  }
  </code></pre>
  
  <p>If I do an authorized request like</p>
  
  <pre><code>http://localhost:27713/api/v1.0/vt
  </code></pre>
  
  <p>.net core answers with a BadRequest:</p>
  
  <pre><code>{"error":{"code":"UnsupportedApiVersion","message":"The HTTP resource that matches the request URI 'http://localhost:27713/api/v1.0/vt' does not support the API version '1.0'.","innerError":null}}
  </code></pre>
  
  <p>What am I missing?</p>