Select a resolution in the options higher than my native 1080p (e.g 1620p or 2160p) to make use of downsampling. Play the game, resolution is higher than native (obvious due to the size of the Steam fps counter and the lack of aliasing). Restart the game, resolution has reverted to native 1080p. This has been an issue since the original release.

Windows 10
Nvidia 980Ti with recent drivers