It doesn’t matter what key combination I set I can’t get the shutdown screen to work.
The logout one does work but not shutdown.
I first noticed the default control-alt-end didn’t work so I tried changing it to control-alt-delete and that doesn’t work either but if I set control-alt-delete back to the logout screen that works fine. It’s a Microsoft Keyboard 600 so pretty basic.
Are you running your Cinnamon desktop on a QEMU virtual machine? If so, in Virtual Machine Manager, go to
Edit > Preferences > Console
and change the Grab keys option to something other than Control_L + Alt_L, which conflicts with Cinnamon’s default shortcuts. For example, I use Control_R.
In your Power Management settings, try changing the When the power management button is pressed setting to Ask, if it’s not set that way all ready. I’m finding that Ctrl+Alt+End is ignored when this option is set to Do Nothing.