Heroku-deployed Django webpage doesn't update when DB changes

I have deployed an app in Heroku using Django. The Django program uses a SQLite database db.sqlite3 on root directory to populate its page. Separately, there is also a Node.js scraper program that inserts to that database.

The problem is that the hard-refreshed webpage shows the same data even after the content of the database changed. Curiously, this does not happen when it is tested locally with python manage.py runserver. How can I fix this problem?

Thank you in advance!

---

For reference, here is my requirements.txt file:

Django==1.10.6  
gunicorn==19.7.1
Pillow==4.0.0
selenium==3.3.1
whitenoise==3.3.0

via sjlee235