“Regular” flash tools are not to be used when flashing modified firmware files, this is “general” rule widely know by the community, as bios/oem vendors prevent’s it, due to security mesasures.
Should be flashed by USB BFB feature as .CAP on selected feature motherboard models.
[Guide] How to flash a modded AMI UEFI BIOS - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum