Read this please, you could start with the output of
$ sudo inxi -Fazy
Maybe the output of the errors in the journal starting from the last boot?
journalctl --boot=-1 --priority=err
Is there any output that could point to a cause in:
$ sudo dmesg -l emerg,alert,crit,err,warn
Why have you set these options and where have you set them? Are you using LVM? (since a quick google leads me to think this is a specific setting if you use LVM )
What is to much time to shutdown and restart? Eg it used to take 10 seconds to shutdown, now it takes 2 minutes.