No, moving the CG back didn't increase the stall speed but it did make the plane more pitch sensitive. So much so that the plane may tend to pitch up as the angle of attack increases and possible pitch down as it decreases. This all becomes more pronounced close to stall or landing speeds. Using power and flattening the glide slope is a typical way to manage this. Or move the cg forward which may be undesirable depending on how you fly the plane

Denis