The custom keyboard shortcut is Ctrl+Alt+k. After using this shortcut, it takes 30-60 seconds for everything to shutdown.
Lately when I do this, the screen will just show the elementary logo on a black background, at which point I have to use the laptop power button to shut it down (can't open terminal, etc.)
FYI I use a Lenovo Ideapad 3, run elementary OS 5.1.7 Hera only, and there are no other distros on my pc.