title: Sudden logout from TYPO3 Backend (TYPO3 CMS 8.5.1)
body: <p>Hi TYPO3 CMS Administrators, Editors and Developers.</p>
  
  <p>Recently I encountered some weird behavior in the latest TYPO3 CMS 8.5.1.
  Sometimes I suddenly get logged out from the backend. I couldn't figure out any pattern when this occurs.
  Sometimes I get logged out when I try to save a page, sometimes it's when saving a TypoScript template, sometimes it happens when I switch from one module to another.
  And before you ask: no, it's not the regular session timeout! It happens within minutes after logging in.</p>
  
  <p>So, I'd just like to know if this has happened to someone else or if it's even a known bug in TYPO3 CMS 8.5.1?
  If you even know how to get rid of this, or things I should check, I'd appreciate your help! :)</p>
  
  <p>About the Webserver:</p>
  
  <ul>
  <li>Debian 8.6</li>
  <li>Apache 2.4.10</li>
  <li>PHP 7.0.14</li>
  <li>TYPO3 CMS 8.5.1</li>
  </ul>
  
  <p>Thanks and happy coding</p>