Smith of Katava Forged in Flame, Coal stoker not giving max lightning RES

Hello,

I have shared my build with several guys online and none of them seem to have an answer to my problem. Maybe I'm overlooking something very simply, but I can't seem to figure whether it's me or a bug.

I am running Smith of Katava with Coal stoker and Forged in Flame. My Fire resistance is 83% (99%), cold resistance 84%(135%), and lightning resistance at 61%.

I don't understand how my lightning is not capped to at least 75% considering that's the whole idea behind forged in flame. My shield has + 29 to lightning res and when I swap to my duel wield hammers my lightning drops even lower to 24%. The other resistances remain untouched.

Forged in flame specifically states: Modifiers to maximum fire resistance also grant maximum Cold and Lightning resistances.

What could be causing this issue? It's rather irritating at this point that I can't seem to find an answer. I'm reaching out in hopes some experts could give their opinion.

Here's my build: https://poe2.ninja/pob/a5b7

On pob.ninja, you got 76% lightning. Forged in flame shares "MAX" resistance. Max normally capped at 75%, you have some +max fire res equipment and passive nodes, so your max cold+ligthning also up..

Now - Let's calculate lightning res after campaign you'll have -40% resistance (considering you picked bonus from act 2) .
+29 shield, and... thats it. So you have -> -40% + 29% = -11% Lightning resistance.
Then we apply Kitavas coal stoker, which is 50% of fire res converts to others. Your uncapped fire is 109%(based on pob) but to get it, you should have 149% (-40 from campaign), so 50% of it is roughly +75% to cold/lightning. This means you should have ~64% Lightning res...

On kitava, just go all in on fire res, change some runes on gear, get fire res rings, and you'll have 200% fire res, which will translate into +100% of lightning/cold, so you'll need just a lil bit to max out all res :)

Hope it helps :)