I don't know what I have changed, but if I am on a terminal and I press Ctrl+a+d (that is, the three keys simultaneously) the terminal is killed. This is on gnome-terminal on Ubuntu and using zsh as the default login shell.
I checked the keyboard shortcuts on gnome-terminal (on the GUI, under Edit->Keyboard Shortcuts) and searched for bindkey statements that may trigger this undesired shortcut in my home directory but found nothing.
I am pretty sure that this is new behavior (last couple of days) since I frequently type Ctrl-a to go to the beginning of a line on my terminal and then Ctr-d to delete characters, and if I do this at the moment, it triggers this undesired keyboard shortcut.
I recently installed some system updates, but I'd be surprised if these updates changed shortcuts. At the moment I have no clue why this is happening, so any help will be greatly appreciated.
Note: This only happens on terminals. If I am on some other app, Ctrl+a+d does not trigger any exit commands.