How to enable A/B update and A/B redundancy

I am struggling to enable A/B update and A/B redundancy on Jetson AGX Xavier following the documentation below
Jetson Xavier NX / AGX Xavier

Edited smd_info.cfg

# SMD metadata information
< VERSION 3 >

#
# Config 1: Disable A/B support (Default)
#

# slot info order is important!
# <priority>    <suffix>     <retry_count>  <boot_successful>
###15                  _a          7               1

#
# Config 2: Enable redundancy support (by removing comments ##)
#
< REDUNDANCY_USER 1 >

# slot info order is important!
# <priority>    <suffix>     <retry_count>  <boot_successful>
15                  _a          7               1
14                  _b          7               1

Then after modifying the smd_info.cfg, the next step is to make the BUP file

Linux_for_Tegra$ 	cd bootloader/
bootloader$ 		sudo ./nv_smd_generator smd_info.cfg slot_metadata.bin

Finally, run the NVIDIA flashing tool:

Linux_for_Tegra$ sudo ./flash.sh -r -k cpu-bootloader jetson-xavier mmcblk0p1

But unfortunately on the target device I don’t have the expected setting

tux@tux-desktop:~$ sudo nvbootctrl dump-slots-info
magic:0x43424e00,             version: 3             features: 0             num_slots: 1
slot: 0,             priority: 15,             suffix: _a,             retry_count: 7,             boot_successful: 1
slot: 1,             priority: 0,             suffix: ,             retry_count: 0,             boot_successful: 0

What is missing there?
Thanks

…an update

Is mandatory to run the NVIDIA flashing tool for the whole system (all partitions again):

Linux_for_Tegra$ sudo ./flash.sh jetson-xavier mmcblk0p1

Now this is the result on the target

tux@tux-desktop:~$ sudo nvbootctrl dump-slots-info
[sudo] password for tux: 
magic:0x43424e00,             version: 3             features: 3             num_slots: 2
slot: 0,             priority: 15,             suffix: _a,             retry_count: 7,             boot_successful: 1
slot: 1,             priority: 14,             suffix: _b,             retry_count: 7,             boot_successful: 1

Hi MarukoBG,

Please try using the nv_update_engine tool to enable redundancy.

  1. Create the BUP image and copy “bl_update_payload” to /opt/ota_package:
    $sudo ./build_l4t_bup.sh jetson-xavier mmcblk0p1
  2. Check current slot:
    $sudo nvbootctrl get-current-slot
  3. Enable A/B redundancy:
    $sudo nv_update_engine --enable-ab
  4. Update engine:
    $sudo nv_update_engine --install