A: THERE ARE TWO POTENTIAL REASON
1: IF CONNECTED TO YOUR TV/MONITOR THAN THE VIDEO BEING OUTPUTTED BY THE VIDEO CABLE WOULD BE IN NON-HD AS THIS IS NOT A HDMI CABLE.
2: THE SETTINGS FOR THE 4K DEVICE MAY NEED TO BE CHANGED FROM THE CURRENT RESOLUTION TO THE 4K RESOLUTION OPTION. TO ACCESS, PLUG YOUR DEVICE INTO THE TV WITH THE PROVIDED VIDEO OUT CABLE AND ACCESS THE MENU.