There's a reasonable chance that the problem of failure to shutdown fully is related to the ACPI power management system since the linux distros that are mentioned have apparently shut themselves down properly, but the message isn't being conveyed to the machine's firmware or software.
Since the problem appears to be intermittent, a reasonable approach to get more information on what is happening is to read (and record) the logs which occur before a successful full shutdown, and read (and record) the logs which occur before a failed full shutdown. The differences in the information may throw some light on the matter.
Logs appear in files such as /var/log/messages, /var/log/syslog, /var/log/kern.log, and are also accessible through using the command: journalctl.
Unfortunately there is a problem with ACPI implementations that companies put into their BIOS/UEFI because they often do not fully apply the ACPI standards which linux does follow, hence the linux kernel will identify as errors the shortcomings it finds in the ACPI implementations.
