Change string automatically inside ion-select

What I am trying to achieve is when I trigger my method "onUpdateMeasure($event)" to update my {{unit}} automatically. With what I’ve done, partially works, it updates the {{unit}} value but only if you click the select (the one with the placeholder " placeholder="My Goal" ". What I want to achieve is when I click the first select and trigger "onUpdateMeasure($event)" to update {{unit}} on the second ion-select automatically, not only when I click on it. If you guys have any idea I would really appreciate it

my HTML

  <ion-select
      [interfaceOptions]="customInterfaceOptions"
      interface="action-sheet"
      (ionChange)="onUpdateMeasure($event)"
        <ion-select-option value="k">k</ion-select-option>
        <ion-select-option value="l">l</ion-select-option>
  </ion-select>

  <ion-select
      [interfaceOptions]="customInterfaceOptions"
      interface="action-sheet"
      placeholder="My Goal">
      <ion-select-option value="l02">{{unit}} per week</ion-select-option>
      <ion-select-option value="l1"> {{unit}} per week </ion-select-option>
    </ion-select>

my TS

    onUpdateMeasure(e) {
       let selection = e.detail.value;
       if (selectiont === "k") {
         this.unit = "kg";
       } else if (selectionWeight == "l") {
         this.unit = "lbs";
    }
  }

This post is 3.5 years old now, but I fear it’s likely still relevant, given the fact that this question still pops up every month or so.