How come I see a blurry, vague box/shadow on the screen when I exit the display menu?
When you turn off the menu on a display, you may briefly observe a blurry/vague box or shadow or gradual brightening of the backlight where you previously saw the on-screen menu.
This phenomenon is caused by a limitation of the processor, as it switches to another way of handling the screen’s lighting when you close the menu. The switch briefly delays the screen's brightness changes right after closing the menu.
Once the backlight has gradually brightened and the remaining ‘shad’ of the on-screen menu has disappeared entirely, your screen should look normal again.
Note: This is not exclusive to Acer products and does not indicate a defect or quality issue with your display.