Then it is your problem you have to resolve (or not). It's not a Vegas problem, where also the latest version 417.71 works without any problem( untill now).
I'm running a Gigabyte GTX 1080 with the 417.35 driver. And that is working "FINE" on Vegas Pro 15, Movie Studio Plat. 15, HitFilm Express, and DaVinci Resolve (free) 15.2.2.
On two monitors as well! Both Samsung 28 inch 4K (UHD).