I have similar problem to you, I brought a 6800xt for a new build to go with my 5900x on a x570 mobo installed windows fine, then try to install the new drivers and software for gpu and get black screen before the installation completes and on start up get black screen. It’s defo a software problem but have no idea what fixes or solutions will come, only way to get running back to normal is using DDU to clean any Amd gpu drivers in safe mode and maybe re install the software you was using before