title: Quasar q-select display nothing when I choose one of the options
body: <p>New to Quasar, and I try to create a <code>q-select</code> that getting as options a list of objects. So far, I achieved to display the options in the dropdown, but when I select an element, the <code>q-select</code> remains empty although the page component data value is filled properly.</p>
  <p>See the following git for more info:</p>
  <p><a href="https://i.stack.imgur.com/jHGDZ.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jHGDZ.gif" alt="enter image description here" /></a></p>
  <p>My <code>q-select</code> implementation is like this:</p>
  <pre><code>&lt;template&gt;
      &lt;!-- ... --&gt;
      &lt;q-select
          v-model=&quot;parentCategory&quot;
          clearable
          use-input
          input-debounce=&quot;350&quot;
          label=&quot;Parent Category&quot;
          :options=&quot;businessCategoriesToSelect&quot;
          :option-label=&quot;opt =&gt; Object(opt) === opt &amp;&amp; 'title' in opt ? opt.title : null&quot;
          :option-value=&quot;opt =&gt; Object(opt) === opt &amp;&amp; '@id' in opt ? opt['@id'] : null&quot;
          :display-value=&quot;Object(parentCategory) === parentCategory &amp;&amp; 'title' in parentCategory ? parentCategory.title : null&quot;
          emit-value
      &gt;
          &lt;template v-slot:no-option&gt;
              &lt;q-item&gt;
                  &lt;q-item-section class=&quot;text-grey&quot;&gt;
                      No Business Categories Found
                  &lt;/q-item-section&gt;
              &lt;/q-item&gt;
          &lt;/template&gt;
      &lt;/q-select&gt;
      &lt;!-- ... --&gt;
  &lt;/template&gt;
  
  &lt;script&gt;
  // ...
  
  export default {
      // ...
      data() {
          return {
              // ...
              parentCategory            : null,
              // ...
              businessCategoriesToSelect: [],
              // ...
          };
      },
      // ...
  }
  &lt;/script&gt;
  </code></pre>
  <p>The objects loaded in the <code>businessCategoriesToSelect</code> have the following form:</p>
  <p><a href="https://i.stack.imgur.com/AGE4e.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AGE4e.png" alt="enter image description here" /></a></p>
  <p>And when I select one of the options in the <code>q-select</code> item the data property that is responsible to hold the selected value it has a value like this:</p>
  <p><a href="https://i.stack.imgur.com/UVLVl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UVLVl.png" alt="enter image description here" /></a></p>
  <p>But although all seems to be OK with what I did, the <code>q-select</code> still don't like to display the proper value.</p>
  <p>Any idea on how to solve that issue?</p>