先帖上关键代码：

var url1 = "https://uatdatarewardsgateway.92jiangbei.com/";

var json = "{\"date\":\"2020-05-21\"}";

string msg1 = string.Empty;

string msg2 = string.Empty;

var result = HttpPost(url1,json,out msg1);

var url2 = "https://test-order-open.i-vpoints.com/";

var result2 = HttpPost(url2, json, out msg2);


        public static string HttpPost(string url,string json,out string msg)
        {
            msg = string.Empty;

            var result = string.Empty;            

            var data = System.Text.Encoding.UTF8.GetBytes(json);

            ServicePointManager.DefaultConnectionLimit = 1024;
            ServicePointManager.Expect100Continue = true;
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3
                | SecurityProtocolType.Tls
                | SecurityProtocolType.Tls11
                | SecurityProtocolType.Tls12;
            ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);

            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;

            request.Method = "POST";

            request.ContentType = "application/json";

            try
            {
                using (var rs = request.GetRequestStream())
                {
                    rs.Write(data, 0, data.Length);
                }
                using (HttpWebResponse wr = request.GetResponse() as HttpWebResponse)
                {
                    using (var wrs = wr.GetResponseStream())
                    {
                        using (var sr = new StreamReader(wrs))
                        {
                            result = sr.ReadToEnd();
                            msg = "OK";
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                msg = ex.Message;
            }

            return result;
        }

===================================================================
以上代码经测试：
1.win7和win2008下面url1无法连接，url2正常；
2.win10下面两个都正常。
3.url1地址在win7下的chrome、firefox、postman等都可以正常访问。
请问怎么处理以上代码在win7和win2008下无法与url1建立https连接？