Issue #2272987 by followup sun: Fixed Do not persist session manager.

core/lib/Drupal/Core/DrupalKernel.php

@@ -703,8 +703,8 @@ protected function initializeContainer($rebuild = FALSE) {
         }
         if ($session_manager->isStarted()) {
           $session_manager_state |= 0x2;
+          $session_manager->save();
         }
-        $session_manager->save();
         unset($session_manager);
       }
     }