I assume that you have the same evaporator as in the LHD model. I'm not sure why a slightly low refridgerant level affects the left side of the evaporator so distinctly, while seemingly not affecting the right side.

At first I thought that perhaps all of the refridgerant is evaporating in the right side and was a warm gas by the time it got over to the left, but now I'm starting to suspect that the left side fills with oil (and starves the compressor).