title: Session expiring in Yii2 despite user activity
body: <p>I have started using Yii2 and need to store more information about user in identity. I already know that in Yii2, this should be done using sessions like </p>
  
  <pre><code>Yii::$app-&gt;session-&gt;set('user.company_id', '121');
  </code></pre>
  
  <p>This works fine as I am able to get these values later in project using:</p>
  
  <pre><code>Yii::$app-&gt;session-&gt;get('user.company_id');
  </code></pre>
  
  <p>. However, these session values are getting wiped up despite user activity on same pages. So after 5-10 minutes, the same user sees some fields based on session value, however, after 1 minute if I refresh the session values go away which should actually happen on session close or user logout.</p>
  
  <p>Any suggestions what I am doing wrong?</p>