I'd be the last person on earth to defend debian or systemd-boot that has turned linux into a garage project, but could it be that you are booting the image in legacy/bios mode and attempt an EFI installation? This is hackish to do since /sys/.../efi.. doesn't exist.
If you insure you are booting in efi mode then it should work out. If not chroot into the installation and follow the procedure of installing the bootloader manually.
apt-get dist-upgrade instead of apt upgrade is debian's way in reconstructing a system victim of the shortcoming of poor package management that can not be healed otherwise.
@acockworkorange @BautAufWasEuchAufbaut