I'm not sure of the internal working of LG, but quite a few of the systems use a thermal sensor on the liquid line to regulate the speed of the outdoor fan (head pressure control).
If a system is overcharged, then the liquid will become very subcooled as it fills up the bottom of the coil. As the sensor is on the outlet pipe from the coil, it see that the liquid is cold and pulls back on the fan revolutions, even to the extent that the fan switches off.
It's difficult to fault find a system charge in cooling mode with low ambients, it takes skill and a good indoor heat load.