When you cloak any projectiles in flight targeting you will still fly at you, and when they hit they pull you out of cloak. NPCs when winding up an AoE attack will still cast it where you were after you turned invisible which is especially noticeable on guards who throw a flare immediately. Cloak in ESO requires some preparation before using if you wish it to actually work like dodge rolling first and then casting it as well as using line of sight denial.