Sounds like a bad quality screen (faulty). Not sure whether you'll be able to get a replacement under warranty from the supplier / seller.
Replacing the screen should fix the issue. Before you replaced the screen, did you clean out any glass fragments on the metal housing where the screen sits if there was any? Also did you put the rubber piece where it sits at the upper end of the logic board? Note that the rubber piece on one side of it is taller and the other side is the opposite. Make sure you put the taller side facing down the logic board / housing side.
This rubber piece is used to stop the LCD + Digitizer front display cable from touching the somewhat sharp edge of the logic board and in result gives the cables a better fit when plugged in.