title: Firefox inspector - CSS rules suggestions/hints
body: <p>I have a problem with the inspector in Firefox browser. After some time of use, in the "rules" tab, system don't want to show me CSS syntax suggestions. After switching the inspector off and on, everything returns back to normal, but ... again ... after a few moments, the system stops showing me syntax hints.</p>
  
  <p><a href="https://i.stack.imgur.com/24qL7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/24qL7.png" alt="firefox inspector rules tab"></a></p>
  
  <pre><code>           with syntax hints                           without syntax hints
                                                      after a couple of minutes
  </code></pre>
  
  <p>Is there any FIX for this? I'm using newest "FireFox Developer Edition" (same thing on normal "Firefox").</p>
  
  <p><strong>UPDATE:</strong>
  I discovered that inspector starts to work improperly when I restart a page which I have been "inspecting".</p>