RaspberryPi CM 3+ up to date image with mender-convert

I’m trying to produce an image with mender-convert for the RaspberryPi Compute Module 3+, without success.
I’m looking for some help if possible.
Here the details.

Source OS image: latest RaspiOS (bookworm based) Index of /raspios_lite_armhf/images/raspios_lite_armhf-2023-10-10
I’ve flashed the board with this image, completed the setup for the first login, updated the OS.

Then I’ve successfully run mender-convert v 4.0.3 against that updated image, with the following configuration:

MENDER_DEVICE_TYPE="lorac"
MENDER_BOOT_PART_SIZE_MB=512
IMAGE_ROOTFS_SIZE=3584000 # 3500 MiB
IMAGE_OVERHEAD_FACTOR=1.0

MENDER_COMPRESS_DISK_IMAGE=gzip
MENDER_ARTIFACT_COMPRESSION=zstd_fast

MENDER_ADDON_CONNECT_INSTALL=y
MENDER_ADDON_CONFIGURE_INSTALL=y

RASPBERRYPI_CONFIG="raspberrypi3"
RASPBERRYPI_KERNEL_IMAGE="kernel7.img"
MENDER_KERNEL_IMAGETYPE="zImage"

source configs/raspberrypi_config

Booting the board with the converted image it seems the boot process do not complete: the following is all the output I get on the serial (GPIO 14 and 15, 115200 Bd)

U-Boot 2020.01-g83cf4883ec (Dec 08 2022 - 09:32:45 +0000)

DRAM:  948 MiB
RPI Compute Module 3+ (0xa02100)

Do you have any suggestion on what else I can try?
Is it possible to have more information from uboot?
Is the version of uboot used by mender-convert up to date?

Thank you!