RAID 1 Doesn't work. FreePBX 15 (2002)

Hi. I'm trying to make a software raid 1 using two identical SATA disks. I'm using FreePBX 15, asterisk 16. I'm using a legacy SATA option. No EFI. 

I have two observations:

ONE: If I try to make a manual RAID 1 installation, all the options trying to make my own configurations on the disks result in an error message. It is impossible to make any change to the disks configurations.

TWO: So, if I choose Asterisk 16 (Recommended), the installation goes fine. It make automatically sync between disks, the partitions are equal, everything looks fine, but if I simulate an error: I turn off the computer, disconnect disk 2 and turn on the computer, the system boots almost to the end of the boot screen then show some errors:

Warning: /dev/SangomaVG/root does not exist

Warning: /devSangomaVG/swaplv1 does not exist

Warning:  /dev/disk/by-id/md-uuid-xxxxxxxxxxx does not exist

Warning:  /dev/disk/by-id/md-uuid-yyyyyyyyyyy does not exist

Warning: /dev/mapper/SangomaVG-R-root does not exist

then gives this  prompt :/#

What I see, is that the Raid 1 is made, but the LVM is broken and then, not only the Raid 1 is useless, but also it needs both disks working fine to operate, which is senseless.

Am I doing something wrong or do we have a bug on the distro?

Thank you.