Windows is no longer showing up in OC or in my Boot Options in BIOS. Anyway to fix this?

I initially created a macOS Mojave install and had the EFI on that drive. I then installed Big Sur on a different drive and installed the EFI for it on the new drive. The Big Sur install seemed bug free, so I formatted the first drive and began to use it solely as storage for the Big Sur drive. Note that Windows is installed on a third drive and that drive was not modified at all. Windows never appeared in the OC boot menu for the Big Sur drive anyway, but after erasing the Mojave drive, Windows Boot Manager is also not appearing in my BIOS boot options

Based on advice from the Discord, I've set BootProtect to None and ScanPolicy to 0. Neither worked however. Anyone have my advice?