one thing that could be helpful (for linux experts) would be to communicate the logs.
In order to keep it at a reasonable length, here is what I propose :
- power on you computer, and once logged in, power it off the regular way
- repeat until the bug manifest and you are forced to shut it down manually
- power it back on, log in
- open a terminal (see much below if you do not know how)
- type
sudo journalctl -b -1 > ~/faulty-shutdown.log.txt - a new file
faulty-shutdown.log.txthas been created in your home folder, open it - copy past the content here
- experts will have a better idea of what is happening.
Once it is done, in the meanwhile I would encourage you to test the shutdown now command in a terminal each time you want to power off, and see if the problem still occurs.
It is because your problem is intermittent I advise you to keep using the shutdown now command for a while. Should the problem not manifest that would narrow down the problem. In that case, executing the command with a keyboard shortcut might be less tedious and make the wait for a resolution more acceptable.
how to open a terminal
press the win key on your keyboard (aka the super key), type cmd and press Return