Proxmox node shutdown/reboot/hang without any useful logs

[okela]

I have a Proxmox node which cannot access today (it shows red cross). I check the syslog and it just say "-- Reboot -- " and something like this

The problem occurs without any useful logs to find the root cause

Can you help me find the cause of this, this is the 3rd time this problem occur in the same Proxmox node. Thank you very much !!!