bug: angular, tabs does not support root path (without /tabs)

[YDrogen]

Bug Report

Ionic version: [x] 4.x

Current behavior: Using the ion-tabs component, clicking on ion-tab-buttons redirect to wrong URL when trying to remove /tabs from tabs.router.module.ts.

Expected behavior: Clicking on one ion-tab-button should redirect to correct URL.

Steps to reproduce:

1. Start a new Ionic Angular project (ionic start tabs-issue tabs --type=angular)
2. Remove /tabs path from tabs.router.module.ts (see related code)
3. Start the app
4. Try navigating from one tab to another

Related code:

const routes: Routes = [
  {
    path: '',
    component: TabsPage,
    children: [
      {
        path: 'tab1',
        children: [
          {
            path: '',
            loadChildren: '../tab1/tab1.module#Tab1PageModule'
          }
        ]
      },
      {
        path: 'tab2',
        children: [
          {
            path: '',
            loadChildren: '../tab2/tab2.module#Tab2PageModule'
          }
        ]
      },
      {
        path: 'tab3',
        children: [
          {
            path: '',
            loadChildren: '../tab3/tab3.module#Tab3PageModule'
          }
        ]
      },
      {
        path: '',
        redirectTo: '/tab1',
        pathMatch: 'full'
      }
    ]
  }
];

Other information: To make it simple - While on /tab1, clicking on the second tab leads me to /tab1/tab2 instead of /tab2

Ionic info:

Ionic:

   ionic (Ionic CLI)             : 4.3.1 (C:\Users\YDrogen\AppData\Roaming\npm\node_modules\ionic)
   Ionic Framework               : @ionic/angular 4.0.0-rc.0
   @angular-devkit/build-angular : 0.11.4
   @angular-devkit/schematics    : 7.1.4
   @angular/cli                  : 7.1.4
   @ionic/angular-toolkit        : 1.2.2

System:

   NodeJS : v8.9.1 (C:\Program Files\nodejs\node.exe)
   npm    : 5.6.0
   OS     : Windows 10