Bought 2 of these monitors here. Picture etc. all ok so far, BUT the two monitors do not go into standby mode properly: They briefly go into standby mode (LED changes from white to red) and then immediately (with black screen) return to normal mode (LED white). Does anyone know this problem? With my previous 2 monitors, with the same settings (and same hardware on the PC), the standby mode worked without any problems. The latest drivers and software are installed. Who can help?