I have recently moved from Linux Mint to Ubuntu MATE (19.10 / 1.22.2). I have been having a problem with shutting down on all my computers and with both Linux Mint and my new Ubuntu MATE. Shut down reboots rather than only shutting down. Since this has happened with more than one OS I am guessing it is a problem with the BIOS setting.
Linux Mint had a tool which nicely displayed all the elements of the system, including the Bios. I can not find such a tool in Ubuntu MATE so I can not provide the name of the Bios. This tool also allowed the user to copy the data so it could be easily shared. Does Ubuntu MATE have such a tool available.
It seemed to install well. I just do not know how to "run it via the terminal". I tried "run inxi" I only got a lot of suggestions to use instead of "run". I do not know what a tool is or how to run one. Can you please explain or point me to a explanation?
You can open the terminal several ways. One of the easier ones is to open the Menu and type Terminal that should open the MATE Terminal and you will have access to the command line.
Be sure to use paste and use tags so it's easy to read on here.
But to the issue - it's likely a kernel / BIOS issue. If this only recently started to happen, it's likely a bug in a newer kernel which might be fixed in a future update. If you knew when it started, then switching to an older kernel could be an option.
You could try a couple of alternate ways of shutting down using the Terminal to observe what happens:
To shutdown then power off:
sudo shutdown -P now
To shutdown and then halt - this is like "freezing" the system, but it is safe to power it off via the button:
sudo shutdown -h now
One setting that might be worth checking in the BIOS is "wake on LAN". This could be starting the computer up after it is supposed to turn off.
tags so it's easy to read on here. 