Падает сервер Socket Io, если вкладка неактивна

    var express = require('express');
var app = express();
var server = require('http').createServer(app);
var io = require('socket.io')(server);
var fs = require('fs');
var https = require('https');
 
server.listen(5000, function () {
    console.log('Server listening at port %d', 5000);
});
const opts = {
    key: fs.readFileSync('/var/www/httpd-cert/olever/site.key'),
    cert: fs.readFileSync('/var/www/httpd-cert/olever/site.crt')
}
 
var httpsServer = https.createServer(opts, app);
httpsServer.listen(5001, function(){
    console.log("HTTPS on port1 " + 5001);
})
 
 
io.attach(httpsServer);
io.attach(server); 
 
io.on('connection', (socket) => {
    console.log('a user connected');
  socket.on('click', function(data) {
        console.log(JSON.stringify(data)+'11');
 
        socket.broadcast.emit('new message', {
            username: socket.username,
            message: data
        });
 
    });
 
 
    let token = socket.handshake.query.token;
    let admin = socket.handshake.query.admin;
        console.log(token);
        socket.join(token);
 
    socket.on(token+'_write', function(msg) {
        console.log( msg['message']);
        if (admin == 1) {
 
            socket.broadcast.emit(token + '_write', {
                username: token,
                message: msg['message']
            });
 
        }
    });
 
    socket.on('disconnect', function() {
        console.log('disconnect');
    });
 
   socket.on(token, function(msg){
 
     if(admin==1) {
         console.log(msg['mess']);
         socket.broadcast.emit(token, {
             username: token,
             message: msg
         });
 
     }
        console.log('message: ' + msg);
if(admin==0) {
    var XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
    var xhr = new XMLHttpRequest();
 
 
    var body = 'my_data=' + encodeURIComponent(JSON.stringify(msg));
 
 
    xhr.open("POST", '/send_chat', true);
    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xhr.send(body);
}
    });
});