title: iOS - `UIViews` behind `UICollectionViewCell`disappear
body: <p>I have a gallery using <code>UICollectionView</code> that prepared using main.storyboard. I have a few <code>UIViews</code> and <code>UIButton</code> placed between <code>UICollectionView</code> and <code>UICollectionViewCell</code>. When I test the app, some of the <code>UIViews</code> and <code>UIButtons</code> disappear. 
  <img src="https://i.stack.imgur.com/Hw5Lh.png" alt="enter image description here"></p>
  
  <p>But I have another catalog scene which prepared using the same way and everything is there. What seems to be the issue?</p>