The Saphe Drive screen uses a different technology than the one you find in various phones, televisions, computer screens and more. This means that it does not emit light, but simply colors some small cells (pixels) black, which means that it uses less power than other technologies, as an image can be shown without the device constantly having to refresh the screen. Instead, it risks freezing the image, so to avoid blurring on the screen from previous images, your Saphe Drive refreshes the screen every 500th times that the image is updated. This means that it removes the color from all cells completely for a few seconds (it becomes completely blank). Subsequently, it again displays images on the screen - you still get alarms during this procedure, just not any icons on the display for 1-2 seconds.
So it is not a defect, but a safety measure that allows you to have a traffic alarm that is easily visible and that does not need very much power, and therefore can hold power for a very long time.
If you have further questions, you are always welcome to Contact support.