title: UIBarButton image drifts into position on when view is rendered
body: <p><a href="https://i.stack.imgur.com/TM2Y7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TM2Y7.png" alt="enter image description here"></a>I have several icons on my toolbar. One of which (highlighted in red) seem to 'drift' into position when view is rendered as if the flexible space kicks in after the image is rendered. Also, the image kind of moves from the adjacent button's top left corner (the filter icon) into position.</p>
  
  <p>This only happens if the app is launched when an update became available while the app was either terminated or was in the background. While I do not understand why, it seems that rendering the default icon in viewDidLoad, followed by server status check and a change of image is the sequence that causes the issue.</p>
  
  <p>Any thought what might cause this behaviour will be appreciated!</p>
  
  <p>Code is very simple:</p>
  
  <pre><code>    if newDataAvailbleOnServer() {
  
      myBarButton.image = cloudWithArrowImage
  
  } else {
  
      myBarButton.image = simpleCloudImage
  
  }
  </code></pre>
  
  <p>both images are of the same size and density. </p>