Form with iterable field

I'm creating a form with some fields can be repeated:

my form:

newSurvey: any = {
    surveyName: '',
    surveyOwner: '',
    questions: [
      { questionTitle: '', values: ['', '', '', '', ''] }
    ]
  };

I have created this structure for the form, where questions can be more than one. And every questions have a question Title and Values

This is the form:

<form (ngSubmit)="createSurvey()">
        <div class="modal-body">
            <label for="surveyName">Name</label>
            <input type="text" id="surveyName" [(ngModel)]="newSurvey.surveyName" name="surveyName" required>
        </div>

       ........

        <div *ngFor="let question of newSurvey.questions; let i = index" class="question">
            <label for="question{{i}}">Question #{{i+1}}:</label>
            <input type="text" id="question{{i}}" [(ngModel)]="question.question" name="question" required>

         
            <label for="values{{i}}">Values: </label>
            <div>
                <input type="text" *ngFor="let value of question.values; let j = index" [(ngModel)]="question.values[j]"
                    name="value" id="value" required>
            </div>

        </div>

        <button type="button" (click)="addQuestion()">Add question</button>

        <div class="modal-footer">
            <button type="button" class="btn btn-outline-dark" type="submit">Create survey</button>
        </div>
    </form>

Now my problem is that when I insert a value in a "Values" Field the same values is wrote in other field.

How can I resolve? Thank you

The problem is that *ngFor renders at every change, to avoid this you can implement tackBy

<input
  type="text"
  *ngFor="let value of question.values; let j = index; trackBy:trackBy"
  [(ngModel)]="question.values[j]"
  name="value"
  id="value"
  required
/>

trackBy(index: number): number {
  return index;
}