I have a Sharp LC-55LBU591C television that I bought recently that shows a flickering in grey colours. It is almost as if the refresh rate of the tv is not lined up with the input, but it happens through the tvs built in roku system as well as through the hdmi input. It can't be seen most times, but it noticeable on a grey desktop backround, or the grey password input screen for the roku netflix app. Ive been able to tone it down a lot by setting the backlight and brightness pretty low, but this is not ideal for viewing in bright rooms. Is this a normal thing that I can address through settings? Or do I have a damaged tv?