title: Region(Circular and Beacon) detection in background sometimes fails in iOS 15
body: <p>We are developing an app that should respond to an iBeacon and circular regions in the background.</p>
  <p>Sometimes it works perfectly, but sometimes the beacon and circular region enter/exit stop suddenly.</p>
  <p>In the app, we are using(in background mode)</p>
  <ul>
  <li>Significant location updates</li>
  <li>Beacon region monitoring</li>
  <li>Circular region monitoring</li>
  <li>Continuous location updates for some actions</li>
  </ul>
  <p>Any idea? It seems to me that in the background regions detection sometimes stopped working suddenly</p>
  <p>Could it be the problem?</p>