TFT Cursed Blade

Hey so i wanted to talk about the Cursed Blade (Attacks have a low chance to Shrink (Reduce enemy's star level by 1). i have noticed whenever an enemy (usually a tier 3) is hit by the effect it would decrease the health to its tier 2 hp. But when the effect wears off and goes back to tier 3 the enemies hp ALSO gets restored to full hp. I was just wondering if the item itself was intended to do that or at least they should lose partial hp when coming back to tier 3.