lock screen shows application list and allows launching apps

[Martin Vysny]

Sometimes the login screen suddenly does not hide the app list. Clicking on individual apps will actually launch that app behind the lock screen.

I haven't found a way to reliably reproduce this issue - it happens "randomly", mostly after I dock/undock laptop, or suspend/resume the laptop, or maybe plug/unplug the monitor.

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: gnome-shell 3.30.1-2ubuntu1
ProcVersionSignature: Ubuntu 4.18.0-11.12-generic 4.18.12
Uname: Linux 4.18.0-11-generic x86_64
ApportVersion: 2.20.10-0ubuntu13.1
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Mon Dec 3 14:18:08 2018
DisplayManager: gdm3
GsettingsChanges:
 b'org.gnome.shell' b'enabled-extensions' b"['<email address hidden>']"
 b'org.gnome.shell' b'command-history' redacted by apport
 b'org.gnome.shell' b'favorite-apps' redacted by apport
 b'org.gnome.desktop.interface' b'gtk-im-module' b"'gtk-im-context-simple'"
 b'org.gnome.desktop.interface' b'scaling-factor' b'uint32 1'
InstallationDate: Installed on 2016-09-05 (819 days ago)
InstallationMedia: Ubuntu-Server 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: gnome-shell
UpgradeStatus: Upgraded to cosmic on 2018-09-28 (66 days ago)

[Martin Vysny (vyzivus)]

Screenshot

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1769383, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.