title: React app changes not updaiting after running npm run build
body: <p>I have a react app with the following file structure:</p>
  
  <p><a href="https://i.stack.imgur.com/bDq94.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bDq94.png" alt="enter image description here"></a></p>
  
  <p>When I run <code>npm run build</code> the app compiles everything using <code>webpack</code> and npm gives me the following output:</p>
  
  <p><a href="https://i.stack.imgur.com/g8Xa2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/g8Xa2.png" alt="enter image description here"></a></p>
  
  <p>In the output (build folder), it creates an <code>asset-manifest.json</code> file, containing the newly created files:</p>
  
  <pre><code>{
    "files": {
      "main.css": "/static/css/main.607e5368.chunk.css",
      "main.js": "/static/js/main.08012c8a.chunk.js",
      "main.js.map": "/static/js/main.08012c8a.chunk.js.map",
      "runtime~main.js": "/static/js/runtime~main.a8a9905a.js",
      "runtime~main.js.map": "/static/js/runtime~main.a8a9905a.js.map",
      "static/css/2.8643d4fb.chunk.css": "/static/css/2.8643d4fb.chunk.css",
      "static/js/2.1aae919f.chunk.js": "/static/js/2.1aae919f.chunk.js",
      "static/js/2.1aae919f.chunk.js.map": "/static/js/2.1aae919f.chunk.js.map",
      "index.html": "/index.html",
      "precache-manifest.ca81004b99ff7fc6f769d98332234f01.js": "/precache-manifest.ca81004b99ff7fc6f769d98332234f01.js",
      "service-worker.js": "/service-worker.js",
      "static/css/2.8643d4fb.chunk.css.map": "/static/css/2.8643d4fb.chunk.css.map",
      "static/css/main.607e5368.chunk.css.map": "/static/css/main.607e5368.chunk.css.map",
      "static/media/index.scss": "/static/media/slick.f97e3bbf.svg"
    }
  }
  </code></pre>
  
  <p>However, if I go into my browser the react app doesn't update and keeps using the old filenames. If I go to the network inspector I can see that the files are loaded with <code>200 OK (from ServiceWorker)</code>.</p>
  
  <p>Why are the newly genrated files not being used in the new index.html?</p>
  
  <p>I've tried clearing my cache, using a clean installation of the template, using another browser, using incognito mode,...</p>