[ionic/angular 4.0.0] FormControl markAs*** not working

Using the Angular Reactive Forms API, when markAsTouched() function is called over a FormControl, the corresponding ion-touched class is not applied to the ion-item (nor to the ion-input). Only the ng-touched is applied.
This problem occurs with each of the markAs*** functions:

  • markAsTouched
  • markAsUntouched
  • markAsDirty
  • markAsPristine
  • markAsPending

Angular Reactive Forms FormControl status classes (ng-XXX) should be paired with the corresponding ion-XXX classes on every FormControl status change.

This is not the first issue I’ve found regarding form control validations. Ionic 4 has a considerable room for improvement in this regard.