No shutdown after cron automatic backup

[SAMI]

Hi,
on a Ubuntu 22.04 64 bits machine, I planed a cron job to backup my files on an external HDD with FreeFileSync (last version 13.7).
I created my cron job with Zeit. The cron job launch well the backup and I checked in FreeFileSync batch "Shutdown at the end", but...
There's no shutdown at the end, but this message :

Impossible d'arrêter le système. (can't stop system)

Failed to set wall message, ignoring: Interactive authentication required.
Failed to power off system via logind: Interactive authentication required.
Failed to start poweroff.target: Interactive authentication required.
See system logs and 'systemctl status poweroff.target' for details.

So, my question is : what is the problem ? where is the problem ? How to solve it ?
Thank you for your answer.

I tried this : launching manually the batch ; backup is OK and Shutdown at the end is OK.

[xCSxXenon]

See system logs and 'systemctl status poweroff.target' for details.

Seems like it might tell you there

[SAMI]

poweroff.target is in disabled status (as state and vendor preset)
But
Am I the only one with this problem ? Never happen before ?...

[xCSxXenon]

https://www.google.com/search?q=Failed+to+power+off+system+via+logind%3A+Interactive+authentication+required

[SAMI]

I already did these searches ; nothing better... always the same problem.

[grimmy30]

Under Linux Mint 22, after backup is run, a countdown window appears. When reaching 0, the computer does not shutdown and a window opens with the following lines :

Error starting "/home/francois/Documents/applis/freefilesync-14.0/Bin/FreeFileSync_x86_64".
Killed by signal 6
<Press a key>

The same cron task executed by hand shuts down the computer, no problem.

$ systemctl status poweroff.target
○ poweroff.target - System Power Off
Loaded: loaded (/usr/lib/systemd/system/poweroff.target; disabled; preset: disabled)
Active: inactive (dead)
Docs: man:systemd.special(7)

FreeFileSync ver 14.0