Technically it should work according to AMD but maybe there is some bug in the driver that prevents it from working currently in this game. The last thing that might help would be to try a "factory reset install" (or whatever it's currently called) of the driver if you haven't tried that already. You get that option early on in the install process and it wipes any previous driver configs which sometimes cause weird problems like these. But there is not much you could do aside of that. We will add a DirectX 12 backend for the game with the upcoming modding update which should also improve compatibility across the board maybe that will help.