ANSWER:

Turns out my app was using SQLite instead of Postgres, due to a problem in database.js file:

To verify which database is being used:

Use heroku logs --tail to check the logs and confirm the connection to PostgreSQL. You should see a table and my table said databse: sqlite

Steps to fix:

1.In database.js file, set the database client dynamically based on NODE_ENV:

const client = env('NODE_ENV', 'development') === 'production' ? 'postgres' : 'sqlite';

2.Make sure the NODE_ENV is set to production

• heroku config:set NODE_ENV=production
• git push heroku master