title: iOS - tab bar turns transparent after dismissing view controller
body: <p>I have encountered a strange behaviour when using the tab bar controller in iOS. I have such a controller with 3 tabs, as can be seen on the following image:</p>
  
  <p><img src="https://i.stack.imgur.com/pcrW9.png" alt="Tab bar"></p>
  
  <p>The following problem only occurs on a physical device, not on the simulator: When I present a view controller (modal) on top and dismiss it again, the tab bar turns fully transparent (not translucent) if and only if it was presented while the map tab was active. If the list or settings tab is active when the view controller is presented, then everything stays as it's supposed to be after dismissing that view controller again.</p>
  
  <p>Has anybody encountered a similar behaviour? Is it a bug? Or am I doing something wrong?</p>
  
  <p>Thank you for your help.</p>