I have the same issue with my DN2820FYKH with an Intel 530 SSD. The SSD disappears after a few writes, once it gets into this state and only a power cycle will bring it back.
Going back to FY0021 BIOS works fine for now as a workaround.
I've opened a case with Intel support and they sent me FY0030 which still has the same issue. They have escalated it to the development team and are working it. It does not seem like a HW issue since others are having it too.