Hi,
sudo systemctl stop media-nano-Z.mount
it really works, but if you forget to do it manually, then when you try to reboot or turn off the single-board computer, it will freeze, because it tries to unmount the disk itself, apparently using umount.
Okay, I did all this after upgrading to Armbian 26.2.0-trunk.86 trixie armv7l, and when I tried to unmount the drive the old way with umount, I found that everything worked. It looks like the problem is already fixed.
tutralex's post in Hang when unmounting cifs filesystem. was marked as the answer