ERROR LOGIN EXPRESS-SESSION

I used session-express to create a login session on a system, but I am having a curious problem, I can log in normally, I have page control, stored sessions in the bank etc, however, sometimes in the system it has an hour that it reaches a "limit" of access and the error of login informing that no user and / or password was found in the bank, being that when access the user remains saved.

I'm using ExpressJS and MongoDB.

Does anyone know what this can be? Here is the code in app.js:

var express = require('express')
var path = require('path')
var favicon = require('serve-favicon')
var logger = require('morgan')
var cookieParser = require('cookie-parser')
var bodyParser = require('body-parser')
var cors = require('cors')

var passport = require('passport')
var session = require('express-session')
var MongoStore = require('connect-mongo')(session)

var index = require('./routes/index')
var employees = require('./routes/employees')
var workzone = require('./routes/workzone')
var proces = require('./routes/process')

var app = express()

app.set('views', path.join(__dirname, 'views'))
app.set('view engine', 'ejs')

app.use(logger('dev'))
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: true }))
app.use(cookieParser())
app.use(express.static(path.join(__dirname, 'public')))


require('./auth')(passport);
app.use(session({
  secret: 'blablabla',
  resave: false,
  saveUninitialized: false,
  store: new MongoStore({
    url: 'mongodb://127.0.0.1:27017/db',
    ttl: 60 * 60,
    autoRemove: 'native'
  }),
}))
app.use(passport.initialize())
app.use(passport.session())

app.use('/', index)
app.use('/employees', employees)
app.use('/workzone', workzone)
app.use('/process', proces)

app.use(function(req, res, next) {
  var err = new Error('Not Found')
  err.status = 404;
  next(err)
})

app.use(function(err, req, res, next) {
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  res.status(err.status || 500)
  res.render('error')
})

module.exports = app;