Hi, thank you for your reply.
After a week of investigation to the problem, trying replacing the bios Bios with multiple versions and searching for problems with the main board itself, i discovered that the problem is due to a bad connection between the M.2 connector and the SSD (too much interference to the SATA Bus).
I solved this problem in a very tricky way, by soldering directly the Sata wires from the SSD to the corresponding pins on the main board, taking care of the SATA Bus specification (grounding, wires capacitance, length matching, ecc…). I also reuse the the SSD Board with the Ezbook to provide the power to the SSD, in order to work.
I hope jumper will solve this problem on future versions of the Ezbook
