title: MUI next Tooltip does not show on hover
body: <p>I use Material-UIv1.0.0-beta.34 Tooltip with Checkbox and FormControlLabel, actually when I hover to the label on Checkbox in one case the tooltip shows as expected on another hand when I create a new one component(custom) with FormControlLabel and Checkbox inside it looks the tooltip does not work as expected.</p>
  
  <p><a href="https://codesandbox.io/s/n33p76n28p" rel="noreferrer">https://codesandbox.io/s/n33p76n28p</a></p>