Podzilla

Hi - I am at my wits end. I have a small cheapo Amazon mini PC (WO-WE H5) with an N150 chip that has been running Unraid without any issues whatsoever for about 8 months now. I have spent considerable time setting up apps, loading important data into file shares, the works. Suddenly, the other night, I ran an update from 7.2.5 to 7.3.1 and went to reboot, and the system has completely locked me out from booting, it throws a red error message at BIOS level saying "Secure Boot Violation - Invalid Signature Detected - Check Secure Boot Policy in Setup". I cannot access any of the secure boot settings in BIOS, they are all grayed out, and I cannot get to anything past the system BIOS. I have seen in the Unraid docs that I need to turn Secure Boot off but I cannot access it, the entire page is grayed out, and no amount of fiddling with BIOS settings has helped. I've tonight tried rolling back the update to the previous version on the USB drive while retaining the config folder to no avail. I have tried many combinations of setting administrator passwords, switching between fast boot on and off, legacy boot/UEFI boot, USB drive in different slots, pulling the CMOS battery and resetting the system clock, etc. This being a cheap Amazon POS mini PC there is effectively zero support for it online, and I can't find anyone else who has had this same combination of issues with a solution. Any help here would be appreciated. Happy to provide any system info needed. Here's what I can copy from the main BIOS screen. I am about to go to MicroCenter and buy a new miniPC to swap the USB and NVME into and hope that gets me further than where I'm at now, but would rather avoid dropping $500 to fix what wasn't a problem over the weekend. Aptio Setup - AMI Bios Version DNB20T V1.01 x64 EC Version 1.09 CPU Intel N150 Manufacturer wo-we product H5 SKU 2501 Bottom of screen - Version 2.22.1293