@panchex - Flash via USB Flashback - http://s000.tinyupload.com/index.php?fil…504425786825391
After flashing, load optimized defaults, save and reboot back to BIOS to make other changes you need.
Then follow all steps at #4 in the “This is what you should do” section of this thread - [Guide] How to get full NVMe support for all Systems with an AMI UEFI BIOS