title: compareWith does not select
body: <p>I have a select option with compareWith but it is not selecting the record in the dropdown list. </p>
  
  <pre><code>&lt;select class="form-control"  name="selectAnswer" [(ngModel)]="Result.answers[i]" [compareWith]="compareFn"&gt;
  &lt;option [ngValue]="answer" *ngFor="let answer of QuestionOption.Answers"&gt;{{answer.description}}&lt;/option&gt;
  </code></pre>
  
  <p>So I have one object Result.answers[i] where i have within an array my selected and saved values (previously saved when creating the record.</p>
  
  <p>In the QuestionOption.Answers I have for all potential Answers for the related question.</p>
  
  <p>Now in the compareFn I compare QuestionOption.Answers with Result.answers[i].</p>
  
  <pre><code>compareFn(c1: any, c2: any): boolean {
        console.log(c1 &amp;&amp; c2 ? c1.id === c2.id : c1 === c2);
           return c1 &amp;&amp; c2 ? c1.id === c2.id : c1 === c2;
      }
  
  </code></pre>
  
  <p>in the console.log I receive true, false, false ...
  So it seems the function returns perfectly fine if c1.id === c2.id</p>
  
  <p>BUT
  in the dropdownlist the record is not selected. It just stays empty.</p>
  
  <p>What do I miss?</p>
  
  <p>Everything seems fine except the selection is not working. What could be the root cause?</p>