Unable to connect to socket.io in production environment - node.js

Question

In development, this is how I was connecting to socket.io:
// server.js
const express = require('express')
const app = express()
const port = 8000
const server = app.listen(port, () =>
console.log(`Server is running on port ${port}`)
);
const io = require('socket.io')(server, {
path: '/socket.io',
pingTimeout: 60000,
cors: {
origin: 'http://localhost:3000',
methods: ['GET', 'POST'],
allowedHeaders: ['Content-type'],
},
maxHttpBufferSize: 1e8,
});
// App.js
import io from 'socket.io-client';
let socket;
const App = () => {
useEffect(() => {
socket = io(
'http://localhost:8000/',
{ path: '/socket.io' },
{ reconnection: true }
);
}
})
It made sense that in production I should just need to change instances of localhost to my domain, however doing so gave me this error:
net::ERR_FAILED 200 (OK)
From research I learned this was a CORS error, so I then amended my domain in App.js to include the port :8000 but then that brings up this error:
net::ERR_CONNECTION_TIMED_OUT
My site in production is running on https and I have amended my domain in both instances accordingly. I have also enabled the uncomplicated firewall through my host. Hoping someone out there can help me to understand what the issue is.