A bit of an odd change, not sure why you would want to show the menu when you press the power button to power Kodi off or suspend it, when there is already several other ways to do the same thing, such as Power Menu, System and press the down button to show Power options (could be the skin with these settings : Aeon Nox: Silvo).
This is the way I fixed it, so when I press the power button on the remote, Kodi powered off, just like it did in 11.0.3.
Create a new file "remote.xml", I did have "keyboard.xml" which worked perfectly well before 11.0.4, and add this code,
<keymap>
<global>
<remote>
<power>shutdown</power>
</remote>
</global>
</keymap>