LG TV Keeps Dimming in Darker Scenes

Hi

So we just bought an 60" LG TV (#60UH6030) and every time there is a darker scence, whether it's a movie or video game, the TV automatically dims to the point where we can barely see anything, literally almost pitch black.
We've fiddled around with the settings for hours, tried every setting from vivid to HDR to original, with all the display options checked off, and no matter what, it still continues to dim in darker scenes.
This had made a very disappointing experience so far and any help would be greatly appreciated.

Thank You