Description of problem:
the second person login on a computer is locked-on after few seconds.

Version-Release number of selected component (if applicable):
gnome-session-3.34.0-2.fc31.x86_64
gnome-session-wayland-session-3.34.0-2.fc31.x86_64
gnome-session-xsession-3.34.0-2.fc31.x86_64
gnome-settings-daemon-3.34.0-1.fc31.x86_64
gnome-shell-3.34.0-2.fc31.x86_64

How reproducible:
100%

Steps to Reproduce:
1. one person logs into his session, then lock the screen.
2. another person logs into his session

Actual results:
The lock screen, with the current time slides dozn within 10 seconds each time the second person logs on.
Even once the first person logs off, the second session works, but a screen corruption occurs, however locking the screen (key meta + l) and login again fix the corruption

Expected results:
multi-user to work as before.

Additional info:
Fedora with all packages up-to-date as of yesterday