Folder portals and full-screen apps

I have encountered a strangely specific problem when using Fences – when I have a folder portal on the desktop, when I switch some games (Assassin’s Creed: Unity and Witcher 3, to be exact) into full-screen mode at resolution less then desktop resolution, the game instantly minimizes, and keeps minimizing every time I try to switch to it. The problem goes away as soon as I remove the folder portal from the desktop.