ASP.NET MVC调用WCF服务报错：无法建立SSL/TLS安全通道

两天前一切运行正常，且未修改任何代码。无需在服务器或本地计算机安装SSL证书，WCF服务的URL（https://sampleurl.com/service.svc）可在浏览器正常打开。控制台应用测试调用服务正常，但在ASP.NET MVC5项目中调用失败。

服务调用代码 #

CustomerServiceClient client = new CustomerServiceClient();
client.ClientCredentials.UserName.UserName = "test@asfasf.com";
client.ClientCredentials.UserName.Password = "asfasf";

var result = client.GetInformation("1MS0274796");

报错信息 #

System.ServiceModel.Security.SecurityNegotiationException: 'Could not establish secure channel for SSL/TLS with authority 'servis.vatanbilgisayar.com'.'

Inner Exception: WebException: The request was aborted: Could not create SSL/TLS secure channel.

已尝试的解决方案 #

调用服务前添加以下代码，但无效：

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

添加证书验证回调后出现新错误：

System.Net.ServicePointManager.ServerCertificateValidationCallback +=
    (se, cert, chain, sslerror) =>
        {
            return true;
        };

新错误信息：

The certificate key algorithm is not supported

项目web.config配置 #

<system.serviceModel>
    <bindings>
        <wsHttpBinding>
            <binding name="CustomerServiceSoap">
                <security mode="TransportWithMessageCredential">
                    <transport clientCredentialType="None" />
                    <message clientCredentialType="UserName" />
                </security>
            </binding>
        </wsHttpBinding>
    </bindings>
    <client>
        <endpoint address="https://xyzx.com/CustomerService.svc"
                  binding="wsHttpBinding" 
                  bindingConfiguration="CustomerServiceSoap"
                  contract="xfasf.asfasf" name="CustomerServiceSoap" />
    </client>
</system.serviceModel>

更新 #

经排查发现，调用服务时需显式调用Open()和Close()方法。若多次调用时未执行此操作，服务可能完全无响应。此前从未出现该问题，此次为突然发生。

内容的提问来源于stack exchange，提问作者MonkeyDLuffy