How to disable automatic lock screen for KDE
Linux systems are normally configured to automatically lock the screen after the user is idle after a set period of time. It is also by default configured to lock the screen when the system wakes up from system sleep or suspend.
For KDE-based distributions such as Kubuntu, the lock screen brings you to SDDM's login screen. Automatic lock screen for KDE can be disabled or configured from KDE's System Settings.
Steps to configure lock screen for KDE:
Launch System Settings from the Application Launcher.
Click on Workspace Behaviour on the sidebar.
Go to Screen Locking panel from the sidebar.
Click on Lock screen automatically checkbox to uncheck and disable the automatic lock screen.
Change the time to set the idle time required to trigger automatic screen lock. Uncheck the After waking from sleep option not to launch screen lock when the system wakes up from sleep.
Click on the Apply button to save the configuration changes.