PC won't boot or display after activating Secure Boot

Specs: CPU: AMD Ryzen 9 5900X,
Motherboard: Gigabyte Aorus X570 Elite Wifi,
RAM: 2x16GB DDR4 Trident G-Skill Neo,
GPU: Asus RTX 3080,
PSU: Gamemax 850W,
OS: Windows 11

So I've updated to Windows 11, and for the newest build of Valorant on W11, Riot has decided to require TPM and Secure Boot to be enabled. I didn't have Secure Boot on, so I entered my Gigabyte BIOS, disabled CSM support (not CSM mode, just support, my disk is in GPT), and enabled Secure Boot, choosing to auto-add the necessary keys. (I only added the keys the 2nd time rebooting, so the system did boot and run with CSM off before I realized I needed to go back.) When I go to reboot, I'm greeted with a blank screen. Nothing I've done has gotten rid of this.

Things I've tried:
Messing with powering on and off the display before booting. (My monitor doesn't play nice with the BIOS, so I already know how to get around that. It doesn't seem to be the issue.)
Booting off an external USB. I didn't expect this to work since, you know, it's not even getting past the BIOS.
Booting without my SSD installed inside the system.
Clearing the CMOS both by removing the battery for several minutes and shorting the two pins.

Other Behavior: When I turn the computer on, the RAM and case RGB lights up, but the keyboard and mouse never do. I have to hold the power button down to get it to turn off.

Things I've seen in other posts that won't work.
Messing with the BIOS settings. I can't get into the BIOS menus at all.
Changing disk partitions to GPT. My disk is NOT legacy CSM, I know I boot in EFI mode, I've seen the volumes before labeled as such, and I did boot without CSM enabled briefly.

There are some similar posts, but they mainly point out the above, which I've tried or won't work. One tidbit I did see is that it might be the Secure Boot BIOS refusing to recognize the GPU? My CPU doesn't have integrated graphics, so I have no way to test this. How would you get around this, if this were hypothetically the case? Also, how is it possible for the Secure Boot to remain past a full CMOS reset? Is there something more that's possible to get rid of it? Like flashing the motherboard again?

Reflashing the motherboard BIOS through Gigabyte's Q-Flash resolved the issue by resetting Secure Boot to off. I used another computer to download the BIOS code file onto a USB, plugged it into a labeled port on the backplate, and held the Q-Flash button for a bit. Search up if your mobo has this, and many guides should exist.