Globalization getLocaleName always return 'en' on iOS12

When the application is run on iOS 12 devices and simulator, the function returns a locale but it always return ‘en’. It does not return the language that is set by the user on the language settings of the phone.

The older iOS versions from iOS 11 and below works okay but iOS 12 does not.

Here is my code snippet with the implementation of getting the locale/language based from the language settings of the phone.

    navigator.globalization.getLocaleName(
      function (locale) {
        $rootScope.language = locale.value.substr(0, 2).toLowerCase();
      },
      function () {
        $rootScope.language = Constants.defaultLanguage; //'en'
      }
    );

Ionic info details:
Ionic CLI Version: 2.2.3
Ionic App Lib Version: 2.2.1
XCode Version: Version 10.0 (10A255)

Anyone with similar problems? I’m open for suggestions.