Issue checking if a ZeroMQ server is ready to talk to clients

I am trying to see if a ZMQ_REP server is ready to communicate with clients using the following code by polling the server every 1 second but it never returns true although the server is up and running for listening to clients.

#include <iostream>#include <zmq.hpp>#include <chrono>const std::string SERVER_ENDPOINT = "tcp://localhost:5555";bool checkServer(const std::string& serverEndpoint) {    zmq::context_t context(1);    zmq::socket_t socket(context, zmq::SocketType::REQ);    socket.connect(serverEndpoint);    zmq::pollitem_t items [] = {{ socket, 0, ZMQ_POLLIN, 0 }};    zmq::poll(items, 1, 1000); // 1 second timeout    if (items[0].revents & ZMQ_POLLIN) {        return true; // If server is available    }    return false;}int main() {    bool serverAvailable = false;    while (!serverAvailable) {        std::cout << "Waiting for server..." << std::endl;        serverAvailable = checkServer(SERVER_ENDPOINT);        std::this_thread::sleep_for(std::chrono::seconds(1));    }    std::cout << "Server is available." << std::endl;    return 0;}

I would appreciate it if someone could shed light on this issue.