Also happened to me this very night. No shutdown in logs, just hang up and had to reboot it. I reinstalled the latest ALARM yesterday to cleanly switch to systemd after two years of usage, something like this never happened.
I noticed that ALARM installer doesn't create a swap partition like the old one did, could this be an issue? I use the Pogo V2 as a seedbox and, maybe, the load was too much and with nowhere to swap on it just crashed. No daemon was replying, pings would timeout etc.