Сбой приложения Heroku - все работает локально

Question

Для моего приложения моя база данных Postgres развернута на AWS, сервер (Node и Express) и клиент (React) отдельно развернуты на Heroku. Мое клиентское приложение продолжает падать, хотя, и я не уверен, почему. Все работает при локальном запуске.

2020-05-01T17:18:33.292129+00:00 app[web.1]: > jepurdy@0.1.0 start /app
2020-05-01T17:18:33.292130+00:00 app[web.1]: > react-scripts start
2020-05-01T17:18:33.292130+00:00 app[web.1]: 
2020-05-01T17:18:36.464174+00:00 app[web.1]: ℹ ｢wds｣: Project is running at http://172.18.97.46/
2020-05-01T17:18:36.464711+00:00 app[web.1]: ℹ ｢wds｣: webpack output is served from
2020-05-01T17:18:36.464811+00:00 app[web.1]: ℹ ｢wds｣: Content not from webpack is served from /app/public
2020-05-01T17:18:36.464902+00:00 app[web.1]: ℹ ｢wds｣: 404s will fallback to /
2020-05-01T17:18:36.465139+00:00 app[web.1]: Starting the development server...
2020-05-01T17:18:36.465140+00:00 app[web.1]: 
2020-05-01T17:18:36.613427+00:00 heroku[web.1]: State changed from starting to crashed
2020-05-01T17:18:37.853487+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=jepurdy.herokuapp.com request_id=01b14ed3-4b6c-44e1-a2c9-7cfbd728b7ad fwd="75.155.134.45" dyno= connect= service= status=503 bytes= protocol=https
2020-05-01T17:18:38.248004+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=jepurdy.herokuapp.com request_id=a3519a2e-1ef9-49be-baa4-d4ed19f9d833 fwd="75.155.134.45" dyno= connect= service= status=503 bytes= protocol=https

Вот пакет. json для клиента:

{
  "name": "jepurdy",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@material-ui/core": "^4.9.7",
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.3.2",
    "@testing-library/user-event": "^7.1.2",
    "axios": "^0.19.2",
    "node-sass": "^4.14.0",
    "react": "^16.13.1",
    "react-dom": "^16.13.1",
    "react-router-dom": "^5.1.2",
    "react-scripts": "3.4.1",
    "react-spinners-css": "^1.1.7",
    "socket.io": "^2.3.0",
    "socket.io-client": "^2.3.0"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  },
  "proxy": "http://localhost:8080"
}