I'm running an Asus G751JM with NVidia GTX-860m 2gb gddr5, intel I-7 4710hq 3.5ghz(4600hd.gpu) 16gbram, running win 10, and the game set to dx12.

Notably this game runs well on my machine, and I did benchmark in both dx11 and dx12 prior to playing.

I was reviewing the video settings, and noticed free-sync was selected. Knowing this shouldn't apply to NVidia, as it's an ati thing, I de-selected it and exited the game

after this, I restarted it, but when selecting dx12, it told me  "unable to initiate video card" and that it was incompatible. So I attempted the dx11, and it launched without a hitch.

 To resolve this I had to completely wipe the game off my computer and re-install. With Free-sync on I am running fine in dx12 mode.