You need CookieCollection to get cookies and set UseCookie to true in HtmlWeb.
CookieCollection cookieCollection = null;
var web = new HtmlWeb
{
//AutoDetectEncoding = true,
UseCookies = true,
CacheOnly = false,
PreRequest = request =>
{
if (cookieCollection != null && cookieCollection.Count > 0)
request.CookieContainer.Add(cookieCollection);
return true;
},
PostResponse = (request, response) => { cookieCollection = response.Cookies; }
};
var doc = web.Load("https://www.google.com");
solved WebRequest not returning HTML