I'm a bit new to Kubuntu (I used other distros but this one only once) and KDE.
I'm having a little problem when shutting down my laptop: when I select "Shut down" in the "Leave" menu and I immediately close the lid of my laptop it suspends instead of shutting down. And if I open the lid it is shows the lock screen for a few seconds and shuts down.
I have checked every setting about suspending when closing the lid and everything. I don't know if I'm missing some setting or it is a problem or a bug.
I used Ubuntu GNOME but I never had this problem with it, I did this with the same laptop but in Ubuntu it shuts down correctly
In Kubuntu 19.10, in the "Energy Savings" setup, there are three places where you can set the machine to suspend when the lid is closed (because there are three tabs: on AC, on battery, and on low battery). You have to check all three.