On win10， a simple req/rep mode，But if the client starts first,Then start the server side.The client will not be able to send any messages.

[nqf]

It seems that connect can't try to connect to the server.Here is my test demo.
client：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

using ZeroMQ;

namespace Examples
{
	static partial class Program
	{
		static public void Main ()
		{

			string endpoint = "tcp://127.0.0.1:5555";

			// Create
			using (var context = new ZContext())
			using (var requester = new ZSocket(context, ZSocketType.REQ))
			{
				// Connect
				requester.Connect(endpoint);
                                Console.Write("sleep\n");
                                Thread.Sleep(10000);
                                Console.Write("sleep endpoint\n");
				for (int n = 0; n < 10; ++n)
				{
					string requestText = "Hello";
					Console.Write("Sending {0}...", requestText);

					// Send
					requester.Send(new ZFrame(requestText));

					// Receive
					using (ZFrame reply = requester.ReceiveFrame()) 
					{
						Console.WriteLine(" Received: {0} {1}!", requestText, reply.ReadString());
					}
				}
			}
		}
	}
}

server：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

using ZeroMQ;

namespace Examples
{
	static class Program
	{
		static public void Main ()
        {
			string name = "hello";

			// Create
			using (var context = new ZContext())
			using (var responder = new ZSocket(context, ZSocketType.REP))
			{
				// Bind
				responder.Bind("tcp://*:5555");

				while (true)
				{
					// Receive
					using (ZFrame request = responder.ReceiveFrame())
					{
						Console.WriteLine("Received {0}", request.ReadString());

						// Do some work
						Thread.Sleep(1);

						// Send
						responder.Send(new ZFrame(name));
					}
				}
			}
		}
	}
}```