title: Scrollbar incorrectly appears underneath UICollectionView section header
body: <p>For some reason my scrollbar always appears underneath the collection view section header. Any help is greatly appreciated! </p>
  
  <p><a href="https://i.stack.imgur.com/k2TtBl.png" rel="noreferrer"><img src="https://i.stack.imgur.com/k2TtBl.png" alt="enter image description here"></a></p>