Uglify Doesn't seem to work

When I ran tns run ios --release --env.uglify or tns build android --release --env.uglify it doesn't seem to Uglify the code at all, I can see the source code and it's readable. Am I doing this wrong somehow?

My app is written with NativeScript core and TypeScript.
My environment:

$ tns doctor
✔ Getting environment information 

No issues were detected.
✔ Your ANDROID_HOME environment variable is set and points to correct directory.
✔ Your adb from the Android SDK is correctly installed.
✔ The Android SDK is installed.
✔ A compatible Android SDK for compilation is found.
✔ Javac is installed and is configured properly.
✔ The Java Development Kit (JDK) is installed and is configured properly.
✔ Xcode is installed and is configured properly.
✔ xcodeproj is installed and is configured properly.
✔ CocoaPods are installed.
✔ CocoaPods update is not required.
✔ CocoaPods are configured properly.
✔ Your current CocoaPods version is newer than 1.0.0.
✔ Python installed and configured correctly.
✔ The Python 'six' package is found.
✔ Xcode version 10.2.1 satisfies minimum required version 9.
✔ Getting NativeScript components versions information...
⚠ Update available for component nativescript. Your current version is 5.4.0 and the latest available version is 5.4.2.
✔ Component tns-core-modules has 5.4.3 version and is up to date.
✔ Component tns-android has 5.4.0 version and is up to date.
✔ Component tns-ios has 5.4.2 version and is up to date.

tns plugin
Dependencies:
┌────────────────────────────────┬─────────┐
│ Plugin                         │ Version │
│ @types/base-64                 │ ^0.1.3  │
│ @types/utf8                    │ ^2.1.6  │
│ base-64                        │ ^0.1.0  │
│ nativescript-camera            │ ^4.4.0  │
│ nativescript-checkbox          │ ^3.0.3  │
│ nativescript-clipboard         │ ^1.1.7  │
│ nativescript-fingerprint-auth  │ ^6.2.0  │
│ nativescript-https             │ ^1.0.3  │
│ nativescript-image-zoom        │ ^3.0.3  │
│ nativescript-mapbox            │ ^4.4.1  │
│ nativescript-masked-text-field │ ^4.0.1  │
│ nativescript-menu              │ ^1.0.3  │
│ nativescript-orientation       │ ^2.2.1  │
│ nativescript-pdf-view          │ ^2.0.1  │
│ nativescript-platform-css      │ ^1.6.7  │
│ nativescript-secure-storage    │ ^2.4.0  │
│ nativescript-social-share      │ ^1.5.1  │
│ nativescript-stripe            │ ^5.0.8  │
│ nativescript-toasty            │ ^1.3.0  │
│ nativescript-ui-listview       │ ^6.1.0  │
│ nativescript-ui-sidedrawer     │ ^6.0.0  │
│ nativescript-videoplayer       │ ^4.2.1  │
│ nativescript-wonderpush        │ ^0.1.1  │
│ rxjs                           │ ~6.3.0  │
│ tns-core-modules               │ ^5.4.0  │
│ utf8                           │ ^3.0.0  │
└────────────────────────────────┴─────────┘
Dev Dependencies:
┌─────────────────────────────┬─────────┐
│ Plugin                      │ Version │
│ nativescript-dev-sass       │ ^1.7.0  │
│ nativescript-dev-typescript │ ~0.7.0  │
│ nativescript-dev-webpack    │ ^0.22.0 │
│ nativescript-theme-core     │ ^1.0.4  │
│ node-sass                   │ ^4.11.0 │
│ tns-platform-declarations   │ ^5.2.0  │
│ tslint                      │ ~5.11.0 │
└─────────────────────────────┴─────────┘

Start by reproducing the issue with the reported tns run ios --release --env.uglify and tns build android --release --env.uglify commands, using the NativeScript and plugin versions listed. Trace the release build's uglification entry point and compare its generated output on both platforms; done means the release output is no longer readable and the behavior is verified for the reported setup.