Webpack 4 doesn't load page in order

I've upgraded to webpack 4 for Rails. I use it with Vue.js 2. I also use chunks in my configuration. But since upgrading, I've noticed that the page load order is weird. The page loads HTML before styles and JS has been loaded, which is not what happened before. I've attached links to the videos for before and after to understand the issue better.

I've been looking in here and everywhere to find anyone with the same issue, but I couldn't...

With Webpack 3(before)

With Webpack 4(after)

Here are my configuration files:

Dev Config

const environment = require('./environment')
const BundleAnalyzerPlugin =
  require('webpack-bundle-analyzer').BundleAnalyzerPlugin;

environment.plugins.append(
  'BundleAnalyzerPlugin',
  new BundleAnalyzerPlugin()
)


module.exports = environment.toWebpackConfig()

Env (shared) Config

const { environment } = require('@rails/webpacker')
const VueLoaderPlugin = require('vue-loader/lib/plugin')
const vue = require('./loaders/vue')

const additionalConfig = {
  plugins: [
    new VueLoaderPlugin(),
  ],
  optimization: {
    splitChunks: {
      cacheGroups: {
        default: false,
        vendor: {
          name: 'vendor',
          chunks: 'all',
          test: /[\\/]node_modules[\\/]/,
          minChunks: 3,
        },
      }
    }
  },
  module: {
    rules: [{
      test: /\.pug$/,
      loader: 'pug-plain-loader'
    }, {
      test: /\.sass$/,
      use: ['vue-style-loader', 'css-loader', 'sass-loader']
    }]
  },
  output: {
  },
  devtool: 'source-map',
}

environment.config.merge(additionalConfig);

environment.loaders.prepend('vue', vue)

module.exports = environment

Pack related to the page in the video

import 'element-ui/lib/theme-chalk/index.css';
import 'element-ui/lib/theme-chalk/display.css';
import 'flexboxgrid/css/flexboxgrid.css';

import Vue from 'vue/dist/vue.esm';
import VueCookies from 'vue-cookies';
import { DateTime } from 'luxon';

// ElementUI Components
import ElementUI from 'element-ui';
import locale from 'element-ui/lib/locale/lang/en';

// Custom Components
import TextSection from '../components/TextSection.vue';
import TopNavigation from '../components/navigation/TheTopNavigation.vue';

import { store } from '../store';

Vue.use(ElementUI, { locale });
Vue.use(VueCookies);

const app = new Vue({
  el: '#app',
  store,
  mounted() {
    var selector = document.querySelector("#app");
    var errors   = selector.dataset.errors;

    if (selector) {
      store.commit('base_states/authenticate',
        JSON.parse(selector.dataset.signedIn)
      );
    }

    if (errors) {
      this.$message({
        dangerouslyUseHTMLString: true,
        message: JSON.parse(errors).join("\n"),
        type: 'error'
      });
    }
  },
  components: { TextSection, TopNavigation },
});

if (!app.$cookies.get('timezone')) {
  app.$cookies.set("timezone", DateTime.local().zoneName);
}

Rails view for that page

#app{ data: { signed_in: "#{user_signed_in?}", errors: flash[:errors] } }
  .landing-top
    .row.banner
      %top-navigation{ ":user" => user, "logo" => logo }
      .row.start-sm.around-sm.middle-sm.center-xs.landing-hero
        .col-lg-4.col-md-4.col-sm-4.col-xs-12
          %h1= t 'static.banner.headline'
          %p= t 'static.banner.subtitle'
          .actions
            %a.no-decoration{ class: "el-button el-button--success", href: "/events" }
              See upcoming events
        .col-lg-6.col-md-6.col-sm-6.col-xs-12
          = video_tag("https://s3.eu-west-2.amazonaws.com/vras-assets/product_preview_new.webm",
                      poster: preview_poster,
                      class: "preview-video", autoplay: "true",
                      muted: "true",          loop: "true" )
  .landing-body.site-padding
    .row.around-lg.middle-lg.middle-md.features
      .col-md-4.col-xs-12.feature-column
        = inline_svg 'icons/potion.svg', class: 'svg-icon'
        %text-section{ "title" => t('static.first_section.title_one'),
                       "text"  => t('static.first_section.text_one') }
      .col-md-4.col-xs-12.feature-column
        = inline_svg 'icons/map.svg', class: 'svg-icon'
        %text-section{ "title" => t('static.first_section.title_two'),
                       "text"  => t('static.first_section.text_two') }
      .col-md-4.col-xs-12.feature-column
        = inline_svg 'icons/unicorn.svg', class: 'svg-icon'
        %text-section{ "title" => t('static.first_section.title_third'),
                       "text"  => t('static.first_section.text_third') }
  .row.center-lg.center-xs.video-showcase
    .col-lg-10.col-md-10.col-xs-12
      = video_tag('https://s3.eu-west-2.amazonaws.com/vras-assets/preview.mp4',
                  poster: 'meta_cover.jpg',
                  class: 'preview-video',
                  autoplay: 'true',
                  muted: 'true',
                  loop: 'true')
    .col-lg-8.col-md-8.col-xs-10{ style: "padding-top: 20px" }
      %h3
        = image_tag("bigscreen_logo.png", width: "250px")
        %br
        = t('static.third_section.title')
      %text-section{ "text"  => t('static.third_section.text') }
  .landing-body.site-padding
    .row.around-lg.middle-lg.middle-md{ style: "margin-bottom: 100px" }
      .col-lg-6.col-md-6.col-xs-12
        %text-section{ "title" => t('static.second_section.title'),
                       "text"  => t('static.second_section.text') }
      .col-lg-6.col-md-6.col-xs-12.first-xs.last-lg.last-md{ style: "text-align: center" }
        %iframe{:title => "Discord Widget", :allowtransparency => "true", :frameborder => "0", :height => "519", :src => "https://discordapp.com/widget?id=402246704252059648&theme=dark", :width => "320"}
  = render "footer"

= javascript_packs_with_chunks_tag 'landing_page'
= stylesheet_packs_with_chunks_tag 'landing_page'

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