App with Firebase not working on Android device but fine in browser

When I run my app which uses Firebase, it runs fine on the browser. However when testing it on an Android device it does not work.
I get a 404 error when trying to load https://www.gstatic.com/firebasejs/3.7.2/firebase.js
I have no idea why this is happening. Can anyone help, please? Thanks!

This is a whitelisting problem. The remote assets (the JS) is blocked by the security constraints. Read up on the whitelist plugin and how to configure and you will be good to go.

Chris