Critical problem with getting Access Token

I am using official Auth0.AuthenticationApi .net library.
When trying to get access token for old clients everything works, but when I try to get token for client, that have been registered today, I get exception:

Auth0.Core.Exceptions.ErrorApiException: Error: certificate has expired
at Auth0.AuthenticationApi.HttpClientAuthenticationConnection.SendRequest[T](HttpRequestMessage request, CancellationToken cancellationToken)
at Auth0.AuthenticationApi.HttpClientAuthenticationConnection.SendAsync[T](HttpMethod method, Uri uri, Object body, IDictionary`2 headers, CancellationToken cancellationToken)
at Auth0.AuthenticationApi.AuthenticationApiClient.GetTokenAsync(ResourceOwnerTokenRequest request, CancellationToken cancellationToken)
at IgsTokenSell.Api.UserAccounts.UserAccountsController.SignIn(SignInRequest request) in C:\Users\szymo\Documents\Projects\igs-token-sell\src\Api\IgsTokenSell.Api\UserAccounts\UserAccountsController.cs:line 57

Version of node used for rules is: 12
Please help me.

Cześć Szymon!

In order to handle that most effectively can I ask you to raise it as a GitHub issue here so the SDK maintainers can help us in addressing that directly:

Once you have a link to it you can share it here so we can ping them. Thanks!