@plegrand UEFI implementations can be a real pain. It’s meant to be Kind of universal but everyone is just doing his/her own thing. So some UEFI clients work great while others just don’t want to play nicely. There is not much we can do about it. Well, you can try using rEFInd and start playing with the config file. If you are lucky it’s justa matter of finding the right options.
P