During on-demand sessions that last an hour or more, the sessions will disappear from the active sessions list while still being active.  This glitch causes major issues if the technician's browser window is accidentally closed or if the technician needs to manage the session from a different browser or computer.  Due to this glitch, I have lost access to a number of hours-long on-demand sessions, which has negatively impacted my IT support workflow.  Please see the screenshots of my currently empty active sessions list and my current 5+ hour session.