Hi,
every time I start the game its in Fullscreen with massive resolution and it completely wrecks my layout on 2 monitors (shifting everything on 1 monitor on background).
Never had any problems, but for the past 1-2 weeks (it might have actually started with the last Nvidia update on August 29) this is happening.
I tried Options in game, tried editing Variables.txt in Documents, and it sometimes works and persists until I shut down PC, after that it goes back to Fullscreen and dont work anymore.
I play Hearthstone as well, and there display setting also were reset at the same time (I think) and game launched in Fullscreen. That was however resolved in Options and persisted since then, working just fine.