Reduced glove DPS why?

Using POB I was comparing my build to a similar one copied from POENinga which used similar items but had a much higher dps. Found swapping to his very similar gloves gave about 20K dps improvement. By editing my gloves to remove “Curse Enemies with Vulnerability on Hit, with 48% increased Effect” gave me that extra 20K dps.

Why should removing that improve the DPS?

Your probably running into a curse limit. Your Blasphemy applies Frostbite and Temporal Chains. You hit, Temporal Chains (I think but not relevant) is removed to apply Elemental Weakness then Vulnerability. Your auras then immediately replace 1 of the on hit curses, and because Elemental Weakness is applied first (alphabetical) it gets replaced.

Have Malediction so thought I was OK to have 2 curses. Forgot that I had Frostbite socketed which POB switched on. Disabled that and difference is now gone.
So you where right thank you.
Since Vulnerability is of no use to my build is there anyway to switch it off so that I can use Frostbite?

Buy new gloves or get +1 curse from boots or ring. You cannot disable the curse though.

OK thanks