Cordova Android Failed to load resource: net::ERR_NAME_NOT_RESOLVED

I have no idea what the issue was but restarting device resolved it. Nothing related to the app, just the phone had difficulties with connecting to Internet even though it was connected to Wi-Fi and signal strength seemed to be on max.

In your app's 'config.xml', place only this:

<allow-navigation href="*" />

And remove what you added to your index.html header. Then if it still doesn't work that means your problem is not related to the whitelist plugin.

I used this plugin in different Android projects and never had to do more than this to allow my app to communicate with the back-end.

Hope that helps!