H723 - unable to enter Bootloader?

Hi !
Having a Manta M8P V2.0 on my desk which uses a STM32H723 controller.
Klipper is flashed and working fine.

I had a lot of F4 boards which could be updated directly using a command like this one:

make flash -j4 FLASH_DEVICE=/dev/ttyACM0

But this seems not to work for H723 controller?

biqu@BTT-CB1:~/klipper$ make flash -j4 FLASH_DEVICE=/dev/ttyACM0
Flashing out/klipper.bin to /dev/ttyACM0
Entering bootloader on /dev/ttyACM0
Device reconnect on /sys/devices/platform/soc/5200000.usb/usb2/2-1/2-1.4/2-1.4:1.0
sudo dfu-util -p 2-1.4 -R -a 0 -s 0x8000000:leave -D out/klipper.bin

dfu-util 0.9

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2016 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to dfu-util / Tickets

dfu-util: Invalid DFU suffix signature
dfu-util: A valid DFU suffix will be required in a future dfu-util release!!!
dfu-util: No DFU capable USB device available

Failed to flash to /dev/ttyACM0: Error running dfu-util

If the device is already in bootloader mode it can be flashed with the
following command:
make flash FLASH_DEVICE=0483:df11
make flash FLASH_DEVICE=1209:beba

If attempting to flash via 3.3V serial, then use:
make serialflash FLASH_DEVICE=/dev/ttyACM0

make: *** [src/stm32/Makefile:111: flash] Error 255

Is there any known problem with this update procedure? It would be possible to use katapult to get the board updated. But using only klipper would make things more easy.


Short Update …
It sometimes works, but often I got an error like above.

Maybe this is a timing issue?

Are you certain it is on ttyACM0 and not on 1 or 2?
ttyACM* devices are allocated numbers in the order they are found so you may be trying to flash the wrong device. This is why klipper communicates with devices as /dev/serial/by-id/xxxxxx once they have the correct software installed.

Klipper and Katapult are complementary. Installing Katapult is a one time effort and then allows you to easily flash the board via make flash FLASH_DEVICE=/dev/serial/by-id/xxxxxx
Updating Katapult or similar maintenance actions are only very rarely needed, if ever.