Lag when using skills or attacking

I lag a lot when I hold down an attack skill too. Holding down a macro key doesn't help much stopping the lag either when I attack. When I fought Ani with my Paladin, I had to tap Blast instead of holding it like I normally would. At least I don't have this much problem when I get to hunt monsters for collecting Crystal Chests by tapping attack skills, but this problem mostly affects me when I boss.