title: Android studio - TextView showing on preview but not emulator/device
body: <p>I started the "Android 6 for Programmers: An App-Driven Approach" book and ran into a problem. I was following the step-by-step approach for one of the apps and got a pretty frustrating error that I cannot fix.</p>
  
  <p>I've added a text and image views and on the Preview section they are shown as they should be but when I run the app on the emulator or on an actual device the text seem to be missing. I am going to attach photos below for more clarity.</p>
  
  <p>The custom colour is Material Blue 500 (#2196F3). Tried changing it to another but the problem doesn't seem to be affected by it.
  The text size is 40sp (80sp on a > 600x600 device).</p>
  
  <p><a href="https://i.stack.imgur.com/JdidX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JdidX.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/mQYLO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mQYLO.png" alt="enter image description here"></a></p>