I have a Desktop PC, when I startup the computer via command line wakeonlan AA:BB:CCD:EE:FF on another PC
It works and the computer boots up and everything ok.

Then I apply the command : sudo shutdown -P now
and then enter the password, it shutdown.

The problem is : when the PC shutdown, power-off, fan stops spin , then it will restart the PC again !
Then, when I apply the same shutdown command again after it completed the bootup, it will shutdown finally, no restart.

So my questions is, the cold boot cannot work, but warm boot seems ok.
Any ideas?