I have the same monitor. Since day 1 I received my monitor it randomly flashes horizontal black line anywhere on the right side of the monitor. I've already tried changing refresh rates, changing different HDMI cables and Displayport cables but still the problem is still there. I'm sure the problem is not with the Mac Mini connected from the monitor because this problem doesn't exist on my old monitor. I also tried connecting iPad and other windows laptop to my Samsung G5 monitor but there is still these thin black lines flashing on my monitor
