Not working \"POLNOEKRANNYJ\" mode. (Fortnite: Battle Royale)

Hello. I have a monitor with a resolution of 1680x1050. The game in a window without frames starts in a resolution my monitor. And if you set the screen parameter fullscreen, the resolution in the game to become 1600x1200. In the settings screen do not have permission 16х10, and there is only 4x3. Please help to resolve this issue. Thank you.