How to fix 'Error: querySrv EREFUSED' when connecting to MongoDB Atlas?

I am new to MongoDB 4.0.6 and tried to implement it into my website using Node/Express.js, but when I try to connect to mongodb+srv://${process.env.MONGOUSER}:${process.env.MONGOPASS}@main-03xkr.mongodb.net/main I'm getting this error:

{ Error: querySrv EREFUSED _mongodb._tcp.main-03xkr.mongodb.net at QueryReqWrap.onresolve [as oncomplete] (dns.js:199:19) errno: 'EREFUSED', code: 'EREFUSED', syscall: 'querySrv', hostname: '_mongodb._tcp.main-03xkr.mongodb.net' }

I've tried connecting to mongodb://localhost:27017/main, but this does seem work.

Here is the relevant code:

require('dotenv').config();
const mongoose = require('mongoose');

// Database
const uri = `mongodb+srv://${process.env.MONGOUSER}:${process.env.MONGOPASS}@main-03xkr.mongodb.net/main`;
const localURI = 'mongodb://localhost:27017/main';

var Project = require('./models/project');

mongoose.connect(uri, { useNewUrlParser: true });
const db = mongoose.connection;

db.once('open', () => console.log('Successfully connected to MongoDB'));
db.on('error', (e) => console.log(e));

// Routes
app.get('/', (req, res) => {
  Project.find({}, (e, projects) => {
    if (e) console.log(e);

    res.render('home.ejs', {
      projects: projects
    });
  });
});

So does anyone know how to fix this error and maybe explain what is happening here?

If you're encountering this error try to use the older connection string for Node.js 2.2.12 or later:

mongodb://<username>:<password>@main-shard-00-00-03xkr.mongodb.net:27017,main-shard-00-01-03xkr.mongodb.net:27017,main-shard-00-02-03xkr.mongodb.net:27017/main?ssl=true&replicaSet=Main-shard-0&authSource=admin&retryWrites=true

According to MongoDB, SRV is possibly not working due to Mongoose.