Версия HTTP запроса

Почему в запросе всё таки Version: 1.1, если использую httpClient.DefaultRequestVersion = new Version(2, 0);

        var httpClientHandler = new HttpClientHandler()
        {
            AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate | DecompressionMethods.Brotli,
            AllowAutoRedirect = true
        };

        HttpClient httpClient = new HttpClient(httpClientHandler);

        httpClient.DefaultRequestVersion = new Version(2, 0);

В запросе:

HttpRequestMessage request = new HttpRequestMessage(System.Net.Http.HttpMethod.Post, "https://***.php");

Вот такие данные:

{StatusCode: 200, ReasonPhrase: 'OK', Version: 1.1, Content: System.Net.Http.HttpConnectionResponseContent, Headers:
{
  Server: nginx/1.18.0
  Date: Sun, 25 Apr 2021 11:14:44 GMT
  Connection: keep-alive
  X-Powered-By: PHP/7.4.8
  Access-Control-Allow-Origin: https://***.ru
  Access-Control-Allow-Credentials: true
  Transfer-Encoding: chunked
  Content-Type: text/html; charset=UTF-8
}}