Lock Screen Failure - Desktop Contents Momentarily Visible

[Free Beachler]

Description: Ubuntu 20.04.2 LTS
Release: 20.04

unity:
  Installed: (none)
  Candidate: 7.5.0+20.04.20200312-0ubuntu1
  Version table:
     7.5.0+20.04.20200312-0ubuntu1 500
        500 http://us.archive.ubuntu.com/ubuntu focal/universe amd64 Packages

Expected:
When waking the monitor/computer with lock screen enabled, the lock screen should be the first visible screen the user sees.

Actual:
When the Ubuntu workstation has lock screen enabled and wakes the monitor (turns it on), the desktop contents are momentarily visible. Furthermore, while desktop contents are visible the desktop is fully interactive, with working mouse, keyboard, and window-interactivity. After a few moments Ubuntu seems to "catch up", hides the desktop contents, and shows the lock screen.

If a malicious user wants to view desktop contents of a sensitive machine, then they can simply record video while waking the monitor.

This problem renders Ubuntu unusable in secure environments. Since this problem has been around since Ubuntu 16, I suspect a design problem that prevents the lock screen from displaying with the highest priority when the monitor wakes.

Ubuntu seems to be the only operating system to have this lock-screen-behavior. Perhaps other *nix desktops have this problem also, rendering them all insecure.

This bug also discussed at https://www.reddit.com/r/gnome/comments/6v5ltb/desktop_contents_briefly_visible_when_waking/