Connection not working from Android to UWP on desktop - ZeroMq (NetMq) - sockets

Question

I tried some examples of ZMQ on C++,C# and Python. I am trying to have Request-Reply pattern to connect Android device to PC running UWP with Xamarin forms.
Below is the Requestor code:
public void HelloWorld()
{
var timer = new Timer(60000);
timer.Start();
timer.Elapsed += (sender, args) =>
{
this.Cancel = true;
timer.Stop();
};
// Create
const string endpoint = "tcp://PC_ip:3245";
using (var request = new RequestSocket())
{
request.Bind(endpoint);
Thread.Sleep(2000);
while (!Cancel)
{
request.SendFrame("Requester says hello");
var reply = request.ReceiveFrameString();
Debug.WriteLine("Gets reply {0}",reply);
}
}
}
Reply socket code:
public void HelloWorld()
{
var timer = new Timer(60000);
const string endpoint = "tcp://PC_ip:3245";
timer.Start();
timer.Elapsed += (sender, args) =>
{
timer.Stop();
Cancel = true;
};
using (var replierSocket = new ResponseSocket())
{
replierSocket.Connect(endpoint);
Thread.Sleep(2000);
while (!Cancel)
{
var replyFromRequester = replierSocket.ReceiveFrameString();
Debug.WriteLine("Got reply {0}", replyFromRequester);
replierSocket.SendFrame("Response socket say hello");
}
}
}
Cancel is boolean
I went through some questions posted on this and added delay and these connection code blocks only trigger after button clicks on app.
While debugging , request.ReceiveFrameString() replierSocket.ReceiveFrameString(); are not even hit.
I am new to network programming , I understand that for REQ/REP pattern the code has to be in particular order which I traced and fixed I believe and turned off firewall on my PC so that firewall wont block my incoming connections from Android device.
PC_ip stands for IPv4 address I got from ipconfig /all for my wifi. I also tried external ip of my machine from sites like whatsmyip.org at ResponseSocket but I still dont get response between devices.
Please let me know what am I doing wrong.
Issue replication repository : GitHub/me/XamZeroMq