at the end!!! 😁😁, my N54L with DSM 6.2.1U4 it shutdown correctly from the DSM OS and reboot perfectly. After differents test I'm not sure what is exactly the real solution: or it's the U4 or the ACPI version 1.0.
With 2.0 and 3.0 not works.
My bios version is from 2011 too.
I hope this help to other people.
I've disabled the embedded NIC Port 1 control, too.