I have the exact same issue. It started after the lates game update. Before that there were no problems whatsoever. After restarting the only solution is to unistall AMD GPU drivers - > restart PC -> install drivers again. The GPU is back and working. I have managed to recreate this problem a second time - it all happened exactly the same way as before. Its 30-60 seconds after the main menu loads in.
Edit: I have to mention that I have the Steam version of the game.
Spec:
AMD Ryzen 9800x3D
AMD Radeon 9070XT
32GB RAM
Windows 10 latest drivers.