Webpack is taking a long time to load Js files

I installed Symfony 6.1.5 with PHP 8.1 on my Ubuntu 20.04 system. I am using nginx 1.18.0 and mysql 5.7. After, I ran a command composer require symfony/webpack-encore-bundle for using encore and ran yarn install. I added my css and js files to the assets folder. And I imported my css and js files in my app.js file. It works fine, but it taking a long time to load. When I open Chrome Network inspection tool, it shows me, that my js files are loading 23 sec and 19 sec. Why so long? How can I fix it?

My webpack.config.js below:

const Encore = require('@symfony/webpack-encore');

// Manually configure the runtime environment if not already configured yet by the 
// "encore" command.
// It's useful when you use tools that rely on webpack.config.js file.
if (!Encore.isRuntimeEnvironmentConfigured()) {
    Encore.configureRuntimeEnvironment(process.env.NODE_ENV || 'dev');
}

Encore
// directory where compiled assets will be stored
 .setOutputPath('public/build/')
// public path used by the web server to access the output path
 .setPublicPath('/build')
// only needed for CDN's or subdirectory deploy
//.setManifestKeyPrefix('build/')

/*
 * ENTRY CONFIG
 *
 * Each entry will result in one JavaScript file (e.g. app.js)
 * and one CSS file (e.g. app.css) if your JavaScript imports CSS.
 */
.addEntry('app', './assets/app.js')

// enables the Symfony UX Stimulus bridge (used in assets/bootstrap.js)
 .enableStimulusBridge('./assets/controllers.json')

// When enabled, Webpack "splits" your files into smaller pieces for greater optimization.
 .splitEntryChunks()

// will require an extra script tag for runtime.js
// but, you probably want this, unless you're building a single-page app
.enableSingleRuntimeChunk()

/*
 * FEATURE CONFIG
 *
 * Enable & configure other features below. For a full
 * list of features, see:
 * https://symfony.com/doc/current/frontend.html#adding-more-features
 */
.cleanupOutputBeforeBuild()
.enableBuildNotifications()
.enableSourceMaps(!Encore.isProduction())
// enables hashed filenames (e.g. app.abc123.css)
.enableVersioning(Encore.isProduction())

// configure Babel
// .configureBabel((config) => {
//     config.plugins.push('@babel/a-babel-plugin');
// })

// enables and configure @babel/preset-env polyfills
.configureBabelPresetEnv((config) => {
    config.useBuiltIns = 'usage';
    config.corejs = '3.23';
})

// enables Sass/SCSS support
//.enableSassLoader()

// uncomment if you use TypeScript
//.enableTypeScriptLoader()

// uncomment if you use React
//.enableReactPreset()

// uncomment to get integrity="..." attributes on your script & link tags
// requires WebpackEncoreBundle 1.4 or higher
//.enableIntegrityHashes(Encore.isProduction())

// uncomment if you're having problems with a jQuery plugin
.autoProvideVariables({
    $: 'jquery',
    jQuery: 'jquery',
    'window.jQuery': 'jquery'
})
;

module.exports = Encore.getWebpackConfig();

My app.js file:

// any CSS you import will output into a single css file (app.css in this case)
import './css/bootstrap.min.css';
import './css/templatemo-style.css';
import './fontawesome/css/all.min.css';


import './js/plugins';

// start the Stimulus application
import './bootstrap';

I just unchecked checkbox with "Disable cache" and now after second loading it works fine. In other words I enabled browser cahce.

Also, my browser has network restrictions (3G on screen). So if you change this setting to 'No restrictions' (or smth), it will be fine.