.net core 2.1 linux系统上任何操作都会报远程证书验证错误

做任何leancloud相关的读写操作都会报如下错误：

 {"ErrorMessage":"The remote certificate is invalid according to the validation procedure.","ErrorType":"System.Security.Authentication.AuthenticationException","StackTrace":["   at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message, AsyncProtocolRequest asyncRequest, ExceptionDispatchInfo exception)","   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)","   at System.Net.Security.SslState.PartialFrameCallback(AsyncProtocolRequest asyncRequest)","--- End of stack trace from previous location where exception was thrown ---","   at System.Net.Security.SslState.ThrowIfExceptional()","   at System.Net.Security.SslState.InternalEndProcessAuthentication(LazyAsyncResult lazyResult)","   at System.Net.Security.SslState.EndProcessAuthentication(IAsyncResult result)","   at System.Net.Security.SslStream.EndAuthenticateAsClient(IAsyncResult asyncResult)","   at System.Net.Security.SslStream.<>c.<AuthenticateAsClientAsync>b__47_1(IAsyncResult iar)","   at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar, Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean requiresSynchronization)","--- End of stack trace from previous location where exception was thrown ---","   at System.Net.Http.ConnectHelper.EstablishSslConnectionAsyncCore(Stream stream, SslClientAuthenticationOptions sslOptions, CancellationToken cancellationToken)"]}

新老版本sdk都是这个错误，似乎是服务器证书问题？昨晚10点之后出现的。

https://www.duoluodeyu.com/2635.html
不知道跟这个有没有关系。我找了另一个用这个证书的网站，访问时报同样的错误。访问百度就正常。

*.api.lncldglobal.com

https://docs.certifytheweb.com/docs/kb/kb-202109-letsencrypt/
昨晚出问题的时间刚好就是证书过期时间。

明白。