Seems that the old session isn't terminate is a normal behaviour, my results for f18/19.
[rave@mother ~]$ loginctl list-sessions SESSION UID USER SEAT 1 1000 rave seat0
1 sessions listed.
[rave@mother ~]$ loginctl list-sessions SESSION UID USER SEAT 1 1000 rave seat0 2 1000 rave seat0
Seems that the old session isn't terminate is a normal behaviour, my results for f18/19.
[rave@mother ~]$ loginctl list-sessions
SESSION UID USER SEAT
1 1000 rave seat0
1 sessions listed.
[rave@mother ~]$ loginctl list-sessions
SESSION UID USER SEAT
1 1000 rave seat0
2 1000 rave seat0