Comment 4 for bug 1415104

This is quite easy to reproduce indeed:

 * Start computer/VM, log in; session c1 (with autologin) or c2 (with manual login) should be the active one.
 * Log out and back in; now c1 should be in state "closing", assuming that there is still some leftover process in it. In my case that's "pulseaudio" (in Seb's case there was some more cruft). The status is still right, c1 is closing, c3 is active.
 * sudo systemctl restart systemd-logind; now c1 becomes "active yes/opening", and c3 is "active no/online".

I guess logind sets the status of all existing sessions at startup (which makes sense), and since both sessions have the same VT/Display it probably just considers the first matching one as active.