Not sure if this has any effect, but if you go to your Documents\My Games\Sid Meier's Civilization VI folder, you will find GraphicsOptions.txt.
There is a line at the very end:
;Set DX12 compute queue usage on (1), off (0), or platform default(-1).
EnableAsyncCompute -1
If you change it to 1, you might get DirectX 12? Unfortunately I don't know how to check which version of DirectX the game is running.