@pistacchio hi
i suggest you re-install the latest version on your sd card and configure it.

LE discord m'a apporté la solution !
Il faut ajouter une entrée dans le grub linux pour RECALBOX.

utilisez grub-customizer pour plus de simplicité

set gfxpayload=auto
set root='(hd1,1)'
search --no-floppy --label --set=root RECALBOX
linux /boot/linux label=RECALBOX console=tty3 quiet loglevel=0
initrd /boot/initrd.gz

remplacer (hd1,1) par le bon disque

Et tout se lance !

Merci de m'avoir lu et merci au betatesteur qui m'a apporté la solution !

@rastaman1201

One more thing to add about editing the systemlist.xml in /recalbox/share/system/.emulationstation/, if you just want to add additional system(s) you don't need any of the other system information in the file, just the new system(s) info you want to add. For example I added a new system for all the trackball games on my arcade, I kept the mame systemlist information in the file and deleted the rest of the info in the file, I then edited the mame system info by changing the fullname, path, and theme. I also changed a few characters in the uuid number/letter chain to make it unique. I'm pretty sure this is also a necessary thing you need to do.

update: now it is definitely working, I had to adjust the screen size to 240p. My problem now is that the image is not well resized, maybe i should try some overscan options. Will look.