I forgot to tell you, about the quick reboot, I have rebooted the quick reboot in the petit boot because I have long used that modified kernel that you see in the guide that you also posted. It is the first operation that is performed before carrying out the whole procedure to install Kernel 5.5.0.RC1 + which brings the Navi 10 patch with me. I still use this Kernel successfully today but I was hoping to be able to use the official one now, here because I ask you to understand what happens in the new official Kernels ...