This sounds like a duplicate of existing similar bug reports. To confirm this, please try waking the machine from sleep but not entering your password. Does the display become obscured a short time after waking still?
** Changed in: gnome-shell (Ubuntu) Status: New => Incomplete ** Changed in: gnome-shell (Ubuntu) Importance: Undecided => High -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1735550 Title: Privacy: One screen not covered on wake after sleep Status in gnome-shell package in Ubuntu: Incomplete Bug description: I have a laptop with an attached HDMI monitor. It is set to require a password after suspension. When I wake the system after suspending it, the laptop display is not obscured. The applications that were running on the laptop display prior to suspension are all visible. The display will become obscured as I start to enter my password. ProblemType: Bug DistroRelease: Ubuntu 17.10 Package: gnome-shell 3.26.1-0ubuntu5 ProcVersionSignature: Ubuntu 4.13.0-17.20-generic 4.13.8 Uname: Linux 4.13.0-17-generic x86_64 ApportVersion: 2.20.7-0ubuntu3.5 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Thu Nov 30 15:37:22 2017 DisplayManager: gdm3 GsettingsChanges: b'org.gnome.shell' b'enabled-extensions' b"['sound-output-device-choo...@kgshank.net', 'grava...@jr.rlabs.io', 'bitcoin-mark...@ottoallmendinger.github.com']" b'org.gnome.shell' b'had-bluetooth-devices-setup' b'true' b'org.gnome.shell' b'app-picker-view' b'uint32 1' b'org.gnome.shell' b'favorite-apps' b"['google-chrome.desktop', 'keepass2.desktop', 'kodi.desktop', 'org.gnome.Nautilus.desktop', 'org.gnome.Software.desktop', 'yelp.desktop', 'calibre-gui.desktop', 'org.gnome.Terminal.desktop', 'virtualbox.desktop', 'org.gnome.Screenshot.desktop']" b'org.gnome.desktop.interface' b'gtk-im-module' b"'gtk-im-context-simple'" InstallationDate: Installed on 2016-03-16 (624 days ago) InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: gnome-shell UpgradeStatus: Upgraded to artful on 2017-10-19 (42 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1735550/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp