Borderless Window / Windowed modes

I work with multiple monitors, and it I often need to look at some things on my desktop area. W

hen Dungeon Alchemist is open and I use Windows+D button, to minimize all windows, the application minimizes, which is great. That's what I want.

But then, when I open any window on any of my 3 monitors, Dungeon Alchemist automatically comes back up and covers the desktop area.

I don't know enough to say if this is a Fullscreen behavior or what, but If it would be at all possible for me to open other stuff and keep Dungeon Alchemist minimized until I call the application itself, that would be a big help for me personally.