upgrading .netcoreapp2.0 to .netcoreapp2.1 starts giving Error parsing discovery document from https://ims.com/.well-known/openid-configuration

Question

Upgraded .NetCoreApp 2.0 to 2.1 and started to get error

Error parsing discovery document from https://ims/.well-known/openid-configuration:

Error connecting to https://ims/.well-known/openid-configuration: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond

Code in Startup.cs ->

services.AddAuthentication()
                    .AddIdentityServerAuthentication(options =>
                    {
                        options.Authority = this.Configuration["Authentication:Authority"];
                        options.ApiName = this.Configuration["Authentication:ApiName"];
                        options.ApiSecret = this.Configuration["Authentication:ApiSecret"];

                        options.EnableCaching = true;
                        options.RequireHttpsMetadata = true;

                         var certException = new CertException(this.Configuration["Authentication:Thumbprint"]);
                            options.IntrospectionDiscoveryHandler = certException.CreateHandler();
                            options.IntrospectionBackChannelHandler = certException.CreateHandler();
                            options.JwtBackChannelHandler = certException.CreateHandler();

                    });

This happens when I am accessing identity server hosted on Cloud from local development visual studio.