i had the same problem with libreelc 9.2.6 installed on a notebook HP dv6000 that have a proprietary remote.
when i pushed the remote power button for the first time i noted a strange behaviour the he ActivateWindow(ShutdownMenu) pop-up and immidiately go to sleep mode
the first thing that i tried is to create a keybord.xml like this:
<keymap>
<global>
<keyboard>
<power>ShutDown()</power>
<sleep>ShutDown()</sleep>
</keyboard>
</global>
</keymap>
with this modify the he Activate Window(ShutdownMenu) stop to poping up but the system goes immidiately in sleep mode.
so i had the idea that the problem was in the linux part a i create lid.confd file with the command:
nano /storage/.config/logind.conf.d/lid.confd
and inside i wrote this:
[Login]
HandlePowerKey=poweroff
HandleSuspendKey=ignore
HandleHibernateKey=ignore
HandleLidSwitch=ignore
PowerKeyIgnoreInhibited=yes
i rebooted the pc and finally it work like i desire when i press the remote power button now the system shutdown completely
hope it help