My problem is that when i power up the system the SSD appears UEFI but after a restart it doesn't, only after powering it down for a while it reappears in the UEFI (sometimes i even needed to take the SSD out for a while, for it to be recognized).

The fartest i could go with the instalation of windows 10 on that SSD was the selection for the bootable device, but after selecting it, it says that there's an error and can't be selected as bootable device anymore (it dissapears again, from the list of both the instalation menu and the UEFI). Im using the latest version of the windows 10 OS fall creators uptade.

I decided to install the OS in a normal sata SSD that i had hanging around, and everything is running fine but the M.2 still doesnt appears in the device nor disk manager after a normal boot.

The SSD is in the list of compatible M.2 disk, and i got the most recent Bios version. i tried disabling the CSM but with no luck.

My system is

CPU: ryzen 5 1600 3.2 ghz

MOBO: Asrock Fatal1ty AB350 gaming K4

PSU:  EVGA 550 watt 80 plus

Ram: Adata 8GB 2400 mhz

HDD: Hitachi 2 TB (for storage only)

SSD: Kingston SSDNow UV400 120 GB