A user triggering a firmware up2date keeps displayed as "logged in" in the "Last Webadmin Sessions" List forever, if the User was still logged in during reboot after firmware up2date - even if the session is finished long time ago...
wingman is correct, he's already reported that issue.
I'm closing this thread as a DUPE. Any further information regarding this issue will be given here: [8.900][BUG] Webadmin sessions not being updated
