Remapping keyboard shortcut seems to depend on power button setting

LM 20.3 beta

Issue
Cannot remap Ctrl-Alt-Delete to Shutdown except with workaround;

Steps to reproduce
Open keyboard settings, shortcuts tab; click on SYSTEM and then LOGOUT, then Ctrl-Alt-Del in bindings box;
Hit backspace to remove and unbind;
Click on SHUT DOWN in keyboard shortcuts box and then replace Ctrl-Alt-End with Ctrl-Alt-Del in the bindings box;
Close keyboard settings;
Test behavior by typing Ctrl-Alt-Del; System will suspend (see "Other information" below);

Expected behaviour
Newly bound Ctrl-Alt-Del will display the shutdown menu

Other information
The behavior of Ctrl-Alt-Del seems to depend on the "When power button is pressed" setting in POWER MANAGEMENT; I had it set to suspend and that's what Ctrl-Alt-Del produced. I changed the power button setting to ASK and Ctrl-Alt-Del now displays the shutdown menu. I changed button behavior back to suspend to confirm and Ctrl-Alt-Del suspended the system. My LM 20.2 install does not have this issue.

Start by reproducing the remapped Ctrl-Alt-Delete behavior in Keyboard settings with the power-button action set to suspend, then repeat with it set to ask. Compare the behavior with the reported Linux Mint 20.2 and 20.3 results; done means the remapped shortcut consistently opens the shutdown menu regardless of the power-button setting.