Invalid Cast Exception when using Subscriptions about graphql-client HOT 2 OPEN

public GraphQLHttpClient Client { get; set; }

var options = new GraphQLHttpClientOptions { HttpMessageHandler = GetInsecureHandler(), EndPoint = new Uri(endpoint) };
Client = new GraphQLHttpClient(options, new NewtonsoftJsonSerializer());

public HttpMessageHandler GetInsecureHandler()
{
    var handler = new CustomAndroidMessageHandler();
    handler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) =>
    {
        if (cert.Issuer.Equals("CN=localhost")) return true;
        return errors == System.Net.Security.SslPolicyErrors.None;
    };
    return handler;
}

internal sealed class CustomAndroidMessageHandler : Xamarin.Android.Net.AndroidMessageHandler
{
    protected override Javax.Net.Ssl.IHostnameVerifier GetSSLHostnameVerifier(Javax.Net.Ssl.HttpsURLConnection connection)
        => new CustomHostnameVerifier();

    private sealed class CustomHostnameVerifier : Java.Lang.Object, Javax.Net.Ssl.IHostnameVerifier
    {
        public bool Verify(string? hostname, Javax.Net.Ssl.ISSLSession? session)
        {
            return
                Javax.Net.Ssl.HttpsURLConnection.DefaultHostnameVerifier.Verify(hostname, session)
                || hostname == "10.0.2.2" && session.PeerPrincipal?.Name == "CN=localhost";
        }
    }
}