io.to(socket.id).emit emitting msg to all connected sockets

I am using socket.io ver 4. When I am trying to send msg to single socket.id it is emitted to all connected socket even though I am sending it to one specific socket.id. Please help me to understand the issue and thanks in advance.

server side

let socketID= socket.id
io.to(socketID).emit("mqtt", {
  sen1: data.sd[0],
  sen2: data.sd[1],
});

client side

  socket.on("mqtt", function (data) {
    console.log("recivers socket", socket.id);
    var sen1 = $("#sen1");
    var sen2 = $("#sen2");

    sen1.html(data.sen1);
    sen2.html(data.sen2);
  });