P2419H, horizontal lines only while turning on

Hi,

While my PC is running, and I turn off the eight month old P2419H (using monitor button), and then I turn it back on, there are some horizontal lines showing up, while the display is black (display is black for a short time while turning on). It can be seen, especially during the day (when sunlight is present). My question:

Is it normal or is my monitor damaged?