The problem with the aspect ratio (Doom (2016))

my monitor is full hd 1920*1080 LG LED 23, but view is not drawn at maximum resolution - you have to put in the settings aspect ratio 16:9 (sounds of the native for the monitor) and the resolution is 1360*768 but for some reason when you select this bit. the game opens not full screen - top and bottom of the frame, although in the settings is full screen, what could be the catch?