G5 5587 NVMe in bios but not OS

Hello, I've had my G5 for around a year now, and decided to do some upgrades. (Ram, hdd, & nvme ssd) each done at a different time and checked to make sure they work. (Nvme being the last)

before upgrading to a 1Tb nvme I dd'd the original drive to a spare partition on my hdd (via Linux) so that i could swap out the drive, boot into linux and just dd the old partitions/data.

after installing the new drive, it showed up in the bios, but was not visible in any os I live booted. Also, it usually just jumpped into the onboard diagnostic instead of performing a live boot.

Any ideas why this might be, and how to get the drive to show up so I can port my data back over?

(Disks are set to Raid mode in the bios btw)