prerender Angular 5 not rendering routes - node.js

Question

Trying to develop a prerendered app following this tutorial
I run a build script which does not throw any errors, creates a dist-prerender folder with an index file and places individual subfolders with the app routes and HTML.
But what I'm finding is, when the subfolders are rendered, they have exactly the same HTML as the index file and nothing corresponding to that route.
In my app.module:
imports: [
BrowserModule.withServerTransition(
{ appId: 'maleon' })
My .angular.cli.json
"name": "prerender",
"platform": "server",
"root": "src",
"outDir": "dist-prerender",
"main": "main.prerender.ts",
"tsconfig": "tsconfig.prerender.json",
"environmentSource": "environments/environment.ts",
"environments": {
"dev": "environments/environment.ts",
"prod": "environments/environment.prod.ts"
}
}
In my package.json
"build": "ng build --prod && ng build --prod --app prerender --output-hashing=none",
"postbuild": "npm run render",
"render": "ts-node prerender.ts"
in prerender.ts
import 'zone.js/dist/zone-node';
import * as path from 'path';
import * as fs from 'fs';
import { enableProdMode } from '#angular/core';
import { renderModuleFactory } from '#angular/platform-server';
import { AppPrerenderModuleNgFactory } from './dist-prerender/main.bundle';
const distFolder = './dist';
const index = fs
.readFileSync(path.resolve(__dirname, `${distFolder}/index.html`), 'utf8')
.toString();
// we could automate this based on the app.routes.ts file but
// to keep it simple let's just create an array with the routes we want
// to prerender
const paths = [
'/about',
'/accountancy',
'/consultancy',
'/taxation',
'/legals',
'/privacy-policy'];
enableProdMode();
// for every route render the html and save it in the correct folder
paths.forEach(p => renderToHtml(p, distFolder + p));
// don't forget to overwrite the index.html as well
renderToHtml('/index.html', distFolder);
function renderToHtml(url: string, folderPath: string): void {
// Render the module with the correct url just
// as the server would do
console.log(folderPath);
renderModuleFactory(AppPrerenderModuleNgFactory, {
url,
document: index
}).then(html => {
// create the route directory
if (url !== '/index.html') {
fs.mkdirSync(folderPath);
}
fs.writeFile(folderPath + '/index.html', html, (err => {
if (err) {
throw err;
}
console.log(`success`);
}));
});
}
I've checked the main.bundle.js that's generated by running the build command, but it's HTML is not extracted