After BIOS Update, OpenCore (0.7.6) won't boot

Hi, hope you’re doing well.

I updated my BIOS (Gigabyte Vision G F21), and now my OpenCore (0.7.6) EFI does not boot. I am not able to reach the picker stage — OpenCore doesn’t appear at all. Everything was working just fine before the BIOS update, so I’ve obviously broken something during the BIOS update.

I have two separate NVMe drives: one with Windows, one with Mac / OpenCore. When I startup, my computer boots straight into Windows. When I enter the BIOS to select a boot device, only my Windows drive appears. There is no OpenCore option.

I am still able to boot into OpenCore/Mac by plugging in an external USB and booting it from BIOS, but I cannot get my native OpenCore EFI to appear at all. My EFI folder still contains all the appropriate files (same as the working USB), so I’m not 100% sure what’s gone wrong.

I’ve tried resetting NVRAM a few times via the USB. I’ve tried changing my Startup Disk to Mac (in System Preferences.) I’ve tried replacing all my EFI files with known working ones. OpenCore will not appear.

One option I haven’t yet tried is removing the Windows NVMe and trying to boot using only Mac, but I’m hoping there’s another solution I can try first, as removing hardware is a bit of a pain. Would re-installing Mac help? Or is there another way I can force my OC EFI to boot?

How can I get my OpenCore EFI back?

Thanks.