Arrogance Support Not Showing Buff

Is it working? There's a little icon in my blasphemy/Impresence supported Flammability saying that the Arrogance gem is recognized but I'm not seeing the buff calculated into the numbers.

I think that curse effect and aura effect are not shown in tooltips, but I might be mistaken.

Unlike the passives on the skill tree, Arrogance does not specify non-curse auras, so I would assume that it applies to the curse effect.

Part of the reason why the curse effect is not reflected in the tooltip might be because enemies can have reduced or less effect of curses on them, so showing only your modifiers and not the enemies' in the tooltip could be considered misleading.

If other curse effect modifiers are included in the tooltip, I might be misremembering. I have not seen the need to check such tooltip in ages since they do not account for as many factors as Path of Building does and are thus unreliable.

You could try testing it in PvP and see if someone's resistance is actually lowered by socketing Arrogance.