Autodesk says NVIDIA is their official card and for good reason.
The only thing I could suggest is get an older driver package first, then completely uninstall the graphics driver (including checking off the box for deleting software), restart the workstation, then install the older driver. Even with upgrading/downgrading/older version drivers, something would either not pop up or just crash the screen. Third, like others in this thread, I've seen bounds of trouble with AMD drivers with Autodesk products. Memory errors of that nature would pop up in different ways during Civil 3D execution. Plenty of capacity and bandwidth and all that jazz. Second, RAM sticks (as opposed to video card memory) is not an issue at all in your instance. A Ryzen 9 3900X would probably be the best bang for the buck if the workstation was built in a different fashion. For the cost of the Silver chip, an i9-10900X would have been a better bargain (10 cores on that chip as well but turbos to 4.5GHz) if you bought a machine from a place like Dell, HP. Your chip turbos out at 3.2GHz, while in comparison a Gold 5218 goes up to 3.9GHz. Very little, if any of the application, will benefit from your setup.
The program relies heavily on a boosted single core as opposed to multi-core/multi-chip.
First off, the CPU spec you have purchased is not ideal for Civil 3D.