_rightEndpoint Race Repro

RRR.cs

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;

namespace UdpMultipleTest
{
    static class Program
    {
        static void Main(string[] args)
        {
            IPEndPoint goodEndpoint = new IPEndPoint(IPAddress.Parse("10.20.30.40"), 12345);
            IPEndPoint badEndpoint = new IPEndPoint(IPAddress.Broadcast, 12345);

            int counter = 0;

            void Print(object msg) => Console.WriteLine($"[{counter}] {msg}");

            byte[] buffer1 = new byte[32];
            byte[] buffer2 = new byte[32];

            void RunExperiment()
            {
                using (Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp))
                {
                    void Good()
                    {
                        socket.BeginSendTo(buffer1, 0, buffer1.Length, SocketFlags.None, goodEndpoint, null, null);
                        if (socket.LocalEndPoint == null) Print("!!!RACE!!!");
                    }

                    void Bad()
                    {
                        try
                        {
                            socket.BeginSendTo(buffer2, 0, buffer1.Length, SocketFlags.None, badEndpoint, null, null);
                        }
                        catch  {  }
                    }

                    Thread good = new Thread(Good);
                    Thread bad = new Thread(Bad);
                    
                    bad.Start();
                    good.Start();

                    bad.Join();
                    good.Join();
                }
                counter++;
            }

            for (int i = 0; i < 2000; i++)
            {
                RunExperiment();
            }
        }
    }
}