Hi, im reviving this thread adding on to a solution, on Maximus Hero viii, bios settings would fallback to default, but clock and notes stays ok, it would not look like de battery is bat, but as if OC went wrong. But no, the battery its bad, in my case it would read 0.66v after replacing it with a new one on 3.0v bios settings work correctly, and no more code A2/A9, of not configured devices enter setup