If it's any consolation, you aren't alone in this issue. I recently switched from a 980 GTX to a Radeon 5600 XT. I thought the swap would be painless but it seems I was sorely mistaken. I uninstalled the nVidia drivers using DDU and even did a fresh install of Windows, but I cannot seem to get the drivers to install properly.
Initially, I managed to get the install software to run and install a driver, but noticed some issues when playing iRacing. I could get 120+ FPS no issue when viewing a replay, but once I started racing, my FPS tanked to 35. I have no explanation for this other than the driver was not installed properly. I've also noticed some other AMD software trying to install on startup, and upon agreeing to install, it tells me that the driver is corrupted and must be reinstalled. Once I try reinstalling, it freezes windows and forces a reboot.
I tried uninstall the driver using DDU (wiped AMD folders and everything), but I keep having the same issue. I've tried installing it in safe mode but it continues to freeze and reboot. I contacted AMD but they haven't responded yet. I'm seriously considering just sending it back and getting an nVidia.