I create the socket like this in the app.js file:

    var express = require('express');
    // Setup server
    var app = express();
    var server = require('http').createServer(app);
    require('./config/express')(app);
    require('./routes')(app);
    var serverHttps = require('https').createServer({ key: privateKey, cert: certificate }, app);
    const socketurl = ['@@socketurl'];
 
    const io = require('socket.io')(server, {
      cors: { origin: socketurl },
      transports: ['websocket'],
    });
 
 
    io.on('connection', (socket) => {  
      global.socket = socket
      socket.emit('init')
    });
 
    .....
 
    exports = module.exports = app;

then, on the server side, in other file (impress.controller.js), I use this socket to emit events like this:

` const waitingOnEmit = global.socket.emitWithAck(‘updateStatusProvaVida’, servidor)

    const emitFailed = new Promise(resolve=>{
      setTimeout(()=>{
          resolve('failed')
      },5000)
    })

    const race = await Promise.race([waitingOnEmit,emitFailed])

    if(race == "failed"){  
      console.error('Error to emit socket: ' + servidor.CPF, error)
      ....
     }
     ....

On the client side, I listen the event like this:

    const socket = io(`${socketurl[0]}`, {
           transports:['websocket', 'polling']     
        });
        socket.on('init', () => {
          console.log('socket iniciado: ' + socket.id)
        })
        socket.on('updateStatusProvaVida', (servidor, ackCallBack) => {         
    
          ackCallBack({status: 200})
        .....
        })

For some reason that I can’t understand, sometimes the emit event is fired, like this:

chrome browser log:
enter image description here

Sometimes, the emit event is even fired:
chrome browser log:
enter image description here

Could you help me figure out what am I doing wrong?
Why sometimes the event is fired? Why sometimes the event is not fired?

Thanks in advance!

I tried use ack to check if the listen will get the event, but the point is that the emit event even is fired.