Angular 9 - Remove default icon (create) on Angular Material Stepper

I'm facing this annoying problem with Angular: I overrode stepper icons by adding in to the provides of the page:

provide: STEPPER_GLOBAL_OPTIONS, useValue: {displayDefaultIndicatorType: false, showError: true}

This is the HTML page (just a piece, there are 7 elements copy/pasted):

<mat-horizontal-stepper>

  <!-- AREA -->
  <mat-step label="Step 1" state="area">
    <p>Put down your phones</p>
    <div>
      <button mat-button matStepperNext>Next</button>
    </div>
  </mat-step>

  <!-- QUESTION -->
  <mat-step label="Step 2" state="question">
    <p>Socialize with each other</p>
    <div>
      <button mat-button matStepperPrevious>Back</button>
      <button mat-button matStepperNext>Next</button>
    </div>
  </mat-step>

  <!-- MODE -->
  <mat-step label="Step 3" state="mode">
    <p>Socialize with each other</p>
    <div>
      <button mat-button matStepperPrevious>Back</button>
      <button mat-button matStepperNext>Next</button>
    </div>
  </mat-step>

...

<!-- Icon overrides -->
  <!-- AREA -->
  <ng-template matStepperIcon="area">
    <mat-icon>gavel</mat-icon>
  </ng-template>

  <!-- QUESTION -->
  <ng-template matStepperIcon="question">
    <mat-icon>contact_support</mat-icon>
  </ng-template>

  <!-- MODE -->
  <ng-template matStepperIcon="mode">
    <mat-icon>forum</mat-icon>
  </ng-template>
...

As you can see, it's just the example you can find on Angular 9 documentation

Well, now let me introduce the problem with several image:

Just look at the circles, they should have inside their own icons (gavel, constact_support, forum). But when I'm on one of those steps, it replaces the icon with another one, to be precise with create icon.

Now, if I come back to the second step, into the circle spawn the correct icon, without this annoying overwriting:

I already tried:

1. Set [completed]=false on <mat-step> component, but it just remove the check icon in to the previous circles
2. Override the icon:

<ng-template matStepperIcon="edit">
  <mat-icon>gavel</mat-icon>
</ng-template>

But it's useless since it just overrides the icon, so the problem still exists. I also tried to leave the <mat-icon></mat-icon> empty, but of course it just leaves a blank icon in to the circle.

What I'm trying to achieve is by-pass this "automatic overwriting". Any idea?

here is the solution it works for me

<mat-horizontal-stepper #stepper>
    <mat-step label="Information">...</mat-step>
    <mat-step label="Groups">...</mat-step>
    <mat-step label="Validate">...</mat-step>
    <ng-template matStepperIcon="number" let-index="index">
        <mat-icon>{{index === 0 ? 'perm_contact_calendar' : index === 1 ? 'group' : 'done'}}</mat-icon>
    </ng-template>
</mat-horizontal-stepper>

@Component({
  selector: 'app-stepper-component',
  templateUrl: './stepper.component.html',
  styleUrls: ['./stepper.component.scss']
})
export class StepperComponent implements AfterViewInit {
  @ViewChild('stepper') stepper: MatHorizontalStepper;
  ngAfterViewInit() {
    this.stepper._getIndicatorType = () => STEP_STATE.NUMBER;
  }
}

Alternatively, override for both matStepperIcon="number" and matStepperIcon="edit":

<mat-horizontal-stepper>
    <mat-step label="Information">...</mat-step>
    <mat-step label="Groups">...</mat-step>
    <mat-step label="Validate">...</mat-step>

    <ng-template matStepperIcon="number" let-index="index">
        <mat-icon>{{index === 0 ? 'perm_contact_calendar' : index === 1 ? 'group' : 'done'}}</mat-icon>
    </ng-template>
    <ng-template matStepperIcon="edit" let-index="index">
        <mat-icon>{{index === 0 ? 'perm_contact_calendar' : index === 1 ? 'group' : 'done'}}</mat-icon>
    </ng-template>
</mat-horizontal-stepper>