login - Cannot Lock Desktop

I had been messing around trying to customize the guest user accoun and came across "Custom startup commands for LightDM guest session", so naturally I clicked it and nothing happened.

Login
However, now I cannot lock my computer when I close the lid or by pressing the dedicated button. I'd like to just make it as it was before I clicked it.

Edit (1)
Output of:
cat /usr/share/lightdm/guest-session/skel/.config/autostart/guest- session-startup.desktop

    [Desktop Entry]
    Name=Custom startup commands for LightDM guest session
    Type=Application
    NoDisplay=true
    Exec=/usr/lib/lightdm/guest-session-auto.sh
    X-Ubuntu-Gettext-Domain=lightdm

Edit (2)
output of /usr/lib/lightdm/guest-session-auto.sh
https://pastebin.com/yvQfnYjk

Edit (3)
output of gsettings list-recursively org.gnome.desktop.lockdown

org.gnome.desktop.lockdown disable-command-line false
org.gnome.desktop.lockdown disable-application-handlers false
org.gnome.desktop.lockdown disable-user-switching false
org.gnome.desktop.lockdown user-administration-disabled false
org.gnome.desktop.lockdown disable-printing false
org.gnome.desktop.lockdown disable-log-out false
org.gnome.desktop.lockdown disable-lock-screen true
org.gnome.desktop.lockdown disable-print-setup false
org.gnome.desktop.lockdown disable-save-to-disk false

output of gsettings list-recursively org.gnome.desktop.lockdown
shows

org.gnome.desktop.lockdown disable-lock-screen true

In order to change it back to false, I had installed dconf-editor using,

sudo apt-get install dcof-editor

Once installed, open the GUI application and follow the path org>gnome>desktop>lockdown>Disable Screen Lockout

Simply remove the checkmark and that was it.