[Ionic 4] Typescript source maps aren't generated when using livereload

Hi there,

If I use npm run ionic cordova run ios -- --source-map --address=0.0.0.0 -l the source maps aren’t generated (or at least the mappings aren’t loaded in Safari) using livereload. But if I use npm run ionic cordova run ios -- --source-map --address=0.0.0.0, the source maps are picked up just fine.

I created a new project with the conference template without any other changes.

Here’s my ionic info:

> ionic-conference-app@0.0.0 ionic /...
> ionic "info"


Ionic:

   Ionic CLI                     : 5.0.2
   Ionic Framework               : @ionic/angular 4.4.2
   @angular-devkit/build-angular : 0.13.9
   @angular-devkit/schematics    : 7.3.9
   @angular/cli                  : 7.3.9
   @ionic/angular-toolkit        : 1.5.1

Cordova:

   Cordova CLI       : 9.0.0 (cordova-lib@9.0.1)
   Cordova Platforms : ios 5.0.1
   Cordova Plugins   : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 4.1.0, (and 5 other plugins)

Utility:

   cordova-res : 0.3.0
   native-run  : 0.2.5

System:

   Android SDK Tools : 26.1.1 (/../Library/Android/sdk)
   ios-deploy        : 1.9.4
   ios-sim           : 8.0.1
   NodeJS            : v11.15.0 (/../.nvm/versions/node/v11.15.0/bin/node)
   npm               : 6.7.0
   OS                : macOS High Sierra
   Xcode             : Xcode 10.1 Build version 10B61

Is this a bug?