C# TCP 使用不同设备但不在本地机器上时丢失数据包

Question

Client code that sends data:

public void SendPointsUpdate(string teamName, int points, bool isHidden)
    {
        if (isDebug)
            return;

        var packet = new PointsUpdatePacket(teamName, points, isHidden);

        var serializedPacket = JsonConvert.SerializeObject(packet);
        var buff = Encoding.ASCII.GetBytes(serializedPacket);
        client.GetStream().Write(buff, 0, buff.Length);
    }

where client is TcpClient

And Server where its received:

while (true)
                {

                    if (client.Connected)
                    {
                        try
                        {
                            if (!client.GetStream().DataAvailable)
                                continue;

                            var buffer = new byte[client.ReceiveBufferSize];
                            client.GetStream().Read(buffer, 0, buffer.Length);

                            var reader = new JsonTextReader(new StringReader(Encoding.ASCII.GetString(buffer)));
                            reader.SupportMultipleContent = true;

                            var packetList = new List<Packet>();
                            try
                            {
                                while (true)
                                {
                                    if (!reader.Read())
                                    {
                                        break;
                                    }

                                    JsonSerializer serializer = new JsonSerializer();
                                    Packet _packet = serializer.Deserialize<Packet>(reader);

                                    packetList.Add(_packet);
                                }

                                foreach (var packet in packetList)
                                {
                                    //var packet = JsonConvert.DeserializeObject<Packet>(Encoding.ASCII.GetString(buffer));

                                    switch (packet.PacketId)
                                    {
                                     //Do stuff
                                    }
                                }
                             }

where client is TcpClient

Now when its running on my local PC (both client and server) Everything works great. When I use another device some packets are lost and not executed. The client device is active all of the time and is sending the packets to the server. That is how 99% of the data transfers are taking place, from client to server. I dont understand why packets are not delivering at all.