Hi, I just want to ask about my device (laptop), when shutdown the device, it's just reboot and not shutdown. So for now, I just can do the shutdown for real at login screen activity (after reboot).
For the most I just ignore this because I do "sleep mode" more often rather than "turn off" my device, but now is bother me, It is normal?
Zorin core 16.2
Can you post the output of
journalctl -b -1 -e
and check your bios wake-on-LAN option is enabled
and try shutting off your computer by these commands and see if it shuts off
poweroff
or
sudo systemctl poweroff
journalctl -b -1 -e
Feb 27 21:57:10 thepegel systemd[1]: Deactivated swap /dev/disk/by-partuuid/8ed25963-be24-4177-9eb3-5ff7d28bd9bf.
Feb 27 21:57:10 thepegel systemd[1]: dev-disk-by\x2dpath-pci\x2d0000:01:00.0\x2dnvme\x2d1\x2dpart9.swap: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Deactivated swap /dev/disk/by-path/pci-0000:01:00.0-nvme-1-part9.
Feb 27 21:57:10 thepegel systemd[1]: dev-disk-by\x2did-nvme\x2dKBG40ZNV512G_KIOXIA_31LPH9AQQH63\x2dpart9.swap: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Deactivated swap /dev/disk/by-id/nvme-KBG40ZNV512G_KIOXIA_31LPH9AQQH63-part9.
Feb 27 21:57:10 thepegel systemd[1]: dev-disk-by\x2did-nvme\x2deui.01000000000000008ce38e0402083d5c\x2dpart9.swap: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Deactivated swap /dev/disk/by-id/nvme-eui.01000000000000008ce38e0402083d5c-part9.
Feb 27 21:57:10 thepegel systemd[1]: dev-nvme0n1p9.swap: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Deactivated swap /dev/nvme0n1p9.
Feb 27 21:57:10 thepegel systemd[1]: dev-disk-by\x2duuid-7d58883a\x2db092\x2d4dd0\x2d82bd\x2d5ed9d849a2dc.swap: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Deactivated swap /dev/disk/by-uuid/7d58883a-b092-4dd0-82bd-5ed9d849a2dc.
Feb 27 21:57:10 thepegel systemd[1]: boot-efi.mount: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Unmounted /boot/efi.
Feb 27 21:57:10 thepegel systemd[1]: systemd-fsck@dev-disk-by\x2duuid-AE54\x2d4AFB.service: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Stopped File System Check on /dev/disk/by-uuid/AE54-4AFB.
Feb 27 21:57:10 thepegel systemd[1]: snap-bare-5.mount: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Unmounted Mount unit for bare, revision 5.
Feb 27 21:57:10 thepegel systemd[1]: snap-snapd-17950.mount: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Unmounted Mount unit for snapd, revision 17950.
Feb 27 21:57:10 thepegel systemd[1]: snap-snapd-18357.mount: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Unmounted Mount unit for snapd, revision 18357.
Feb 27 21:57:10 thepegel systemd[1]: Stopped target Mounting snaps.
Feb 27 21:57:10 thepegel systemd[1]: home.mount: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Unmounted /home.
Feb 27 21:57:10 thepegel systemd[1]: Reached target Unmount All Filesystems.
Feb 27 21:57:10 thepegel systemd[1]: systemd-fsck@dev-disk-by\x2duuid-4887d317\x2dc403\x2d4d7b\x2d84ab\x2d1e26c7c2d4c6.service: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Stopped File System Check on /dev/disk/by-uuid/4887d317-c403-4d7b-84ab-1e26c7c2d4c6.
Feb 27 21:57:10 thepegel systemd[1]: Removed slice system-systemd\x2dfsck.slice.
Feb 27 21:57:10 thepegel systemd[1]: Stopped target Local File Systems (Pre).
Feb 27 21:57:10 thepegel systemd[1]: systemd-tmpfiles-setup-dev.service: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Stopped Create Static Device Nodes in /dev.
Feb 27 21:57:10 thepegel systemd[1]: systemd-sysusers.service: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Stopped Create System Users.
Feb 27 21:57:10 thepegel systemd[1]: systemd-remount-fs.service: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Stopped Remount Root and Kernel File Systems.
Feb 27 21:57:10 thepegel systemd[1]: Reached target Shutdown.
Feb 27 21:57:10 thepegel systemd[1]: Reached target Final Step.
Feb 27 21:57:10 thepegel systemd[1]: systemd-poweroff.service: Succeeded.
Feb 27 21:57:10 thepegel systemd[1]: Finished Power-Off.
Feb 27 21:57:10 thepegel systemd[1]: Reached target Power-Off.
Feb 27 21:57:10 thepegel systemd[1]: Shutting down.
Feb 27 21:57:10 thepegel systemd-shutdown[1]: Syncing filesystems and block devices.
Feb 27 21:57:10 thepegel systemd-shutdown[1]: Sending SIGTERM to remaining processes...
Feb 27 21:57:10 thepegel systemd-journald[293]: Journal stopped
that log has been taken after rebooting (actually it is using command "poweroff")
confirmed
That command did the "shutdown" for real, but just for the first try, meanwhile I do same command to turn off the laptop again at different time but it end up with rebooting. What wrong?
Fascinating. And then it boots back up?
Yes, it boot back up to grub.
The computer indeed shutdown 
Have you checked this?
Yes it's ON/enabled
do I need necessary to disable this?
Yes disable it and check
It's great to hear your problem has been resolved. 
This would worry me. If your computer is getting a wake signal from the LAN, you may want to check who has access to your network, what devices have access and what others are doing.
Probably not solved yet. This night I shutdown my laptop, but it boot up again "restarting".
so I come a cross to see the log, here my log after "restarting"
7:05:50 PM systemd: Failed to start Application launched by gnome-session-binary.
7:05:48 PM gdm-session-wor: gkr-pam: unable to locate daemon control file
7:05:40 PM wpa_supplicant: nl80211: Failed to create a P2P Device interface p2p-dev-wlp0s20f3
7:05:40 PM wpa_supplicant: nl80211: Failed to create a P2P Device interface p2p-dev-wlp0s20f3
7:05:40 PM wpa_supplicant: Failed to create interface p2p-dev-wlp0s20f3: -22 (Invalid argument)
7:05:40 PM wpa_supplicant: nl80211: kernel reports: Attribute failed policy validation
7:05:37 PM kernel: ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20210730/psparse-529)
7:05:37 PM kernel: ACPI Error: Aborting method \_SB.PC00.XHCI.RHUB.HS01._PLD due to previous error (AE_NOT_FOUND) (20210730/psparse-529)
7:05:37 PM kernel: ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20210730/psargs-330)
7:05:37 PM kernel: ACPI Error: Aborting method \_SB.PC00.TXHC.RHUB.SS01._PLD due to previous error (AE_NOT_FOUND) (20210730/psparse-529)
7:05:37 PM kernel: ACPI BIOS Error (bug): Could not resolve symbol [\_SB.UBTC.RUCC], AE_NOT_FOUND (20210730/psargs-330)
7:05:37 PM kernel: integrity: Problem loading X.509 certificate -65
I see over there is mention about kernel: integrity X.509 certificate , ACPI BIOS Error problem etc. I don't know what it is.
Then I realised my "secure boot" is ON, which that I can't turn it OFF via BIOS.
It is possible any correlation between that?
this result of terminal command that I found from here that had same issue of (kernel: integrity X.509 certificate).
journalctl -b -k | grep -i efi
Feb 28 19:05:37 thepegel kernel: efi: EFI v2.70 by INSYDE Corp.
Feb 28 19:05:37 thepegel kernel: efi: ACPI=0x45bfe000 ACPI 2.0=0x45bfe014 TPMFinalLog=0x45ae5000 SMBIOS=0x439e3000 SMBIOS 3.0=0x439e1000 MEMATTR=0x3e9c4018 ESRT=0x3ebe9818 MOKvar=0x3e8cd000 RNG=0x45b7a018 TPMEventLog=0x300b3018
Feb 28 19:05:37 thepegel kernel: efi: seeding entropy pool
Feb 28 19:05:37 thepegel kernel: Kernel is locked down from EFI Secure Boot mode; see man kernel_lockdown.7
Feb 28 19:05:37 thepegel kernel: ACPI: UEFI 0x0000000045B2E000 000236 (v01 XMCC XMCC2039 00000001 ACPI 00040000)
Feb 28 19:05:37 thepegel kernel: ACPI: Reserving UEFI table memory at [mem 0x45b2e000-0x45b2e235]
Feb 28 19:05:37 thepegel kernel: clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645519600211568 ns
Feb 28 19:05:37 thepegel kernel: pci 0000:00:02.0: BAR 2: assigned to efifb
Feb 28 19:05:37 thepegel kernel: Registered efivars operations
Feb 28 19:05:37 thepegel kernel: efifb: probing for efifb
Feb 28 19:05:37 thepegel kernel: efifb: showing boot graphics
Feb 28 19:05:37 thepegel kernel: efifb: framebuffer at 0x4000000000, using 8100k, total 8100k
Feb 28 19:05:37 thepegel kernel: efifb: mode is 1920x1080x32, linelength=7680, pages=1
Feb 28 19:05:37 thepegel kernel: efifb: scrolling: redraw
Feb 28 19:05:37 thepegel kernel: efifb: Truecolor: size=8:8:8:8, shift=24:16:8:0
Feb 28 19:05:37 thepegel kernel: fb0: EFI VGA frame buffer device
Feb 28 19:05:37 thepegel kernel: EFI Variables Facility v0.08 2004-May-17
Feb 28 19:05:37 thepegel kernel: integrity: Loading X.509 certificate: UEFI:db
Feb 28 19:05:37 thepegel kernel: integrity: Loading X.509 certificate: UEFI:db
Feb 28 19:05:37 thepegel kernel: integrity: Loaded X.509 cert 'Microsoft Corporation UEFI CA 2011: 13adbf4309bd82709c8cd54f316ed522988a1bd4'
Feb 28 19:05:37 thepegel kernel: integrity: Loading X.509 certificate: UEFI:db
Feb 28 19:05:37 thepegel kernel: integrity: Loading X.509 certificate: UEFI:db
Feb 28 19:05:37 thepegel kernel: integrity: Error adding keys to platform keyring UEFI:db
Feb 28 19:05:37 thepegel kernel: integrity: Loading X.509 certificate: UEFI:MokListRT (MOKvar table)
Feb 28 19:05:37 thepegel systemd[1]: Starting Load Kernel Module efi_pstore...
Feb 28 19:05:37 thepegel kernel: pstore: Registered efi as persistent store backend
Feb 28 19:05:37 thepegel systemd[1]: modprobe@efi_pstore.service: Succeeded.
Feb 28 19:05:37 thepegel systemd[1]: Finished Load Kernel Module efi_pstore.
My kernel is default Zorin 5.15.0-60-generic #66~20.04.1-Ubuntu
Me too, but actually my device is not connecting to network when it happened, not even LAN (wired) is plug in. So it's weird.
Since my laptop power button is build-in on keyboard so I set "do nothing" when press in down the button, but let I try.
Confirm, I doing this 3 time, and yes it did "shutdown" as expected
But I don't want to turn off my device using that way...
Does your computer have any usb mouse or keyboard connected?
and does it shutdown when connected to AC?
It is a harmless error generally.
AE_NOT_FOUND means that a specification is not set - or not set correctly. When the system looks for it, it cannot find it and therefor has to fall back to a generic or default specification.
You figured this one out already:
That is your cause on this one.
If you cannot disable Secure Boot - what you can do is configure MOK on Zorin OS to respect the Secure Bootup List.
I just installed Zorin OS 16.2 Core on my second Lenovo ThinkCentre Mini Desktop and I have the same issue. When doing a shutdown the system does a reboot. Initially, I thought it was a bios issue since I was receiving a "Checking Media Presence... start PXE over IPv4" error. So, I removed the network boot from the bios startup order and the error message went away but it still reboots instead of shutting down.
Questions from a newbie: where do I find the logs noted above and where do I find the "wake on LAN' in bios?
OK, so I finally found the "wake-on-LAN" setting in the bios and disabled it. Now the system does a proper shutdown.
However, on boot, I noticed the following error messages:
x86/cpu: VMX (outside TXT) disabled by BIOS
ima: Error Communicating to TPM chip
What does it mean and what should I do about it?
You can copy and paste the commands you read so far on Terminal and press Enter. Then you can view all system logs on Logs.
Check this 
Thanks