msi Can't change boot mode in new motherboard?

[Pingable Username]

Recently I rebuilt my system to swap my motherboard and upgrade my CPU. (MSI PRO Z790-P WIFI and I7-12700K)

 

The system POSTs fine, I have good thermals, and everything is detected, but no matter what I do, my original boot drive (XPG SX8200 M.2) will NOT show up as an option in the boot order.

 

I've noticed my boot mode is greyed out, and locked into UEFI. I think that's the issue, but no matter what I try I absolutely cannot get it to change. I even turned off secure boot, but that didn't unlock the option...

 

I'd really prefer to just be able to boot into my M.2, is there a way through this?

 

(I know in theory I could just make another UEFI-friendly Windows install on a different drive, but I have data on all of my drives :/)

 

OS: Windows 10 Pro 64 bit (I would tell you the version, but I can't check it right now for obvious reasons)

CPU: I7-12700K (Base clock)

RAM: 4x8 DDR4 LPX Vengance 3200mhz

GPU: Gigabyte AORUS Elite RTX 3060

Mobo: MSI PRO Z790-P WIFI

Storage: ADATA XPG SX8200 PRO M.2 1TB

SK Hynix Gold S31 SSD 500GB

Seagate Barracuda 7200RPM HDD 2TB

BIOS:E7E06IMS.110 (09/01/2022)

 

[Pingable Username]

gee, thanks for the replies, guys