IonicModule.forRoot() does not work in lazy loaded module

I would like to separate the Ionic project from another project by lazy loading the Ionic.
So, as I used to do, I created a mobileModule and imported IonicModule.forRoot() there like this:

@NgModule({
  declarations: [
    MobileComponent
  ],
  imports: [
    CommonModule,
    MobileRoutingModule,
    IonicModule.forRoot(),
  ],
  providers: [{ provide: RouteReuseStrategy, useClass: IonicRouteStrategy }],
})
export class MobileModule { }

And lazy loaded this module in the app-routing.module:

@NgModule({
  imports: [
    RouterModule.forRoot([
      {
        path: '',
        loadChildren: () =>
          import('./views/mobile/mobile.module').then((m) => m.MobileModule),
      },
    ]),
  ],
  exports: [RouterModule],
})
export class AppRoutingModule {}

The CSS file is loaded. The size of mobileModule is around 1MB so the module is added. But all I see is a blank page.

As soon as I import IonicModule.forRoot() to the appModule, everything works fine. But the vendor file size will be increased to around 1MB. So, obviously, the Ionic module is now added to the vendor.

My question is why it works in the appModule and not in the mobileModule.

Note that it was working with @ionic/angular@5.3.1

My package.json:

"dependencies": {
    "@angular/animations": "^14.1.0",
    "@angular/common": "^14.1.0",
    "@angular/compiler": "^14.1.0",
    "@angular/core": "^14.1.0",
    "@angular/forms": "^14.1.0",
    "@angular/platform-browser": "^14.1.0",
    "@angular/platform-browser-dynamic": "^14.1.0",
    "@angular/router": "^14.1.0",
    "@ionic/angular": "^6.2.7",
    "rxjs": "~7.5.0",
    "tslib": "^2.3.0",
    "zone.js": "~0.11.4"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "^14.1.2",
    "@angular/cli": "~14.1.2",
    "@angular/compiler-cli": "^14.1.0",
    "@types/jasmine": "~4.0.0",
    "jasmine-core": "~4.2.0",
    "karma": "~6.4.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage": "~2.2.0",
    "karma-jasmine": "~5.1.0",
    "karma-jasmine-html-reporter": "~2.0.0",
    "typescript": "~4.7.2"
  }