Dear Maintainer,
* What led up to the situation?
Select a command line in GRUB-menu ("c") and enter "halt to shutdown the PC.
Acording to official documentation on grub 2.06 (https://www.gnu.org/software/grub/manual/grub/grub.html paragraph 16.3.31) it should perform a shutdown using APM.
After every "halt" command the PC powers off and at next boot my NVMe-SSD, Samsung 980 has the SMART-attribute "unsafe shutdowns" increased by 1.
This indicates that the SSD's Buffers have not been transferred to NAND before the power is cut.
Remark: said SSD uses host memory buffer (HMB), a technique becoming popular.
Those unsafe shutdowns do NOT happen when I perform a "poweroff" or "shutdown -h" on a booted system (here Bookworm).
I tried to verify that it is not a single issue by discussing this issue in the German debianforum and got the same beheaviour on similar hardware confirrmed.
https://debianforum.de/forum/viewtopic.php?t=186800#p1326586