Wayland or X11?
Can you check if there's any warnings on powerdevil?

X11; Wayland session isn't even available with base packages from default setup, I would need to install additional ones (which I can, though KDE isn't the main environment I'm using).

Not many logs nor useful ones I think, but just incase, here's what can be found from journalctl after locking session and pressing esc a couple of times:

```
févr. 24 19:32:47 T470-clement kscreenlocker_greet[206224]: Qt: Session management error: networkIdsList argument is NULL
févr. 24 19:32:47 T470-clement kscreenlocker_greet[206224]: file:///usr/lib/qt/qml/QtQuick/Controls.2/ToolButton.qml: QML IconImage: Error decoding: file:///usr/share/icons/breeze-dark/actions/24/edit-copy.svg: Unsupported image format
févr. 24 19:32:47 T470-clement kscreenlocker_greet[206224]: kf.kirigami: Failed to find a Kirigami platform plugin
févr. 24 19:32:47 T470-clement kscreenlocker_greet[206224]: file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/components/VirtualKeyboard.qml:8:1: module "QtQuick.VirtualKeyboard" is not installed
févr. 24 19:32:47 T470-clement plasmashell[1237]: qt.qpa.clipboard: QXcbClipboard::setMimeData: Cannot set X11 selection owner
févr. 24 19:32:47 T470-clement kscreenlocker_greet[206224]: file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/lockscreen/MediaControls.qml:82:9: QML Image: Binding loop detected for property "sourceSize.height"
févr. 24 19:32:47 T470-clement plasmashell[1237]: qt.qpa.clipboard: QXcbClipboard::setMimeData: Cannot set X11 selection owner
févr. 24 19:32:49 T470-clement dbus-daemon[486]: [system] Activating via systemd: service name='org.freedesktop.home1' unit='dbus-org.freedesktop.home1.service' requested by ':1.592' (uid=1000 pid=206224 comm="/usr/lib/kscreenlocker_greet --immediateLock --gra")
févr. 24 19:32:49 T470-clement dbus-daemon[486]: [system] Activation via systemd failed for unit 'dbus-org.freedesktop.home1.service': Unit dbus-org.freedesktop.home1.service not found.
févr. 24 19:32:49 T470-clement kscreenlocker_greet[206224]: pam_systemd_home(kde:auth): systemd-homed is not available: Unit dbus-org.freedesktop.home1.service not found
```

Can you paste the output of `systemctl status --user plasma-powerdevil.service`?

$ systemctl status --user plasma-powerdevil.service
● plasma-powerdevil.service - Powerdevil
     Loaded: loaded (/usr/lib/systemd/user/plasma-powerdevil.service; static)
     Active: active (running) since Thu 2023-02-23 18:57:38 CET; 3 days ago
   Main PID: 1269 (org_kde_powerde)
      Tasks: 7 (limit: 9352)
     Memory: 5.9M
        CPU: 46.763s
     CGroup: /user.slice/user-1000.slice/user@1000.service/background.slice/plasma-powerdevil.service
             └─1269 /usr/lib/org_kde_powerdevil

févr. 23 18:57:37 T470-clement systemd[976]: Starting Powerdevil...
févr. 23 18:57:38 T470-clement systemd[976]: Started Powerdevil.
févr. 23 18:57:38 T470-clement org_kde_powerdevil[1269]: org.kde.powerdevil: Handle button events action could not check for screen configuration
févr. 25 14:21:26 T470-clement org_kde_powerdevil[1269]: org.kde.powerdevil: Failed to start suspend job "org.freedesktop.login1.OperationInProgress" "There's already a shutdown or sleep operation in progress"
févr. 27 07:46:46 T470-clement org_kde_powerdevil[1269]: org.kde.powerdevil: Unsatisfied policies, the action has been aborted
févr. 27 07:46:51 T470-clement org_kde_powerdevil[1269]: org.kde.powerdevil: Unsatisfied policies, the action has been aborted

Ok looks like it's running. But those warnings make me think it might be be working properly.

What distro are you using?

(In reply to Nate Graham from comment #5)
> Ok looks like it's running. But those warnings make me think it might be be
> working properly.
> 
> What distro are you using?

Up-to-date ArchLinux.
This is a years-old setup (including KDE's install), with pretty much the default settings of the installation time.

Thanks for the info.

I'm running Plasma 5.27.8 on X11 on Manjaro Linux (which itself is based on Arch Linux). I have two monitors. Pressing Escape doesn't turn off the displays for me either. And apparently other people are also facing this issue: https://www.reddit.com/r/kde/comments/1149tzi/monitor_doesnt_turn_off_when_i_press_esc_on_the/

Bug 423035 is a somewhat related bug. People would like to lock and turn off the screen, but bug 423035 prevents that. Most likely, because the KeyRelease event from triggering the shortcut happens after the display was asked to turn off, and thus the system understands it's a new input and turns the display back on immediately. Could it be the same root cause for this bug?

`systemctl status --user plasma-powerdevil.service` shows it is active and running. There are three messages, most of them seem unrelated:
* org.kde.powerdevil: org.kde.powerdevil.chargethresholdhelper.getthreshold failed "Charge thresholds are not supported by the kernel for this hardware"
* org.kde.powerdevil: org.kde.powerdevil.backlighthelper.brightness failed
* org.kde.powerdevil: Handle button events action could not check for screen configuration

Also running into this issue on openSUSE Tumbleweed. 

Laptop (X1 Carbon 6th gen) with two external monitors, laptop is closed.

Plasma 5.27.8
Kernel 6.5.6-1-default (64-bit)
Graphics platform X11
Graphics processor Mesa Intel® UHD Graphics 620

Same on Arch Linux running Plasma 6 alpha and neon untstable.

This was fixed as documented further down in bug 338796. The brief version is that the turn-off handler wasn't executed because on X11 initialization finished before it could register for the "initialization finished" signal. The fix will be in Plasma 6.0 RC2 and later.