the reason your humidity went up is because there is moisture bound up in the inner cells of the bud, which is working its way to the outer cells and from there into the air in the jar. when you dry the outer cells lose their moisture first, being closest to the air. when you cure, you are allowing the bud to redistribute the moisture in the middle of the buds to remoisten the outer cells of the bud and lose more moisture to the air in the jar, until it reaches an equilibrium where the entire bud has the same amount of moisture through and through at around 55% rh. as a poster above said, go read the stickies on drying and curing for more info.