Elemental Weakness on maps

Elemental Weakness on (Tier 16) maps seems kinda funny.

Elemental Weakness on high tier maps should be level 15 (https://pathofexile.gamepedia.com/Elemental_Weakness#Elemental_Weakness_in_maps), which should be -34% to all elemental resistances.

My character (Guardian) has "25% reduced Effect of Curses on You" from "Time of Need" so, according to the wiki (https://pathofexile.gamepedia.com/Curse), I should have a Curse Effect of (1 * (1 + 0 - 0.25) * 1 * 1 = 0.75 (right?).

Being so I should have 34 * 0.75 = 25.5% reduced elemental resistances but I am getting -50% to all elemental resistances in tier 16 maps with elemental weakness (haven't tested the other maps).

I have The following resistances:

Fire 83% (123%)
Cold 81% (115%)
Lightning 82% (115%)

... and in maps I end up with:

Fire 73%
Cold 65%
Lightning 65%

Did something change in the last patch? Am I missing something here (besides resistances)?