Elemental weakness map mod doubles in strength sometimes

Hi here's the image showing and describing the bug.

Might also happen with other curses, I wouldn't know how to check (check tooltip for enfeeble maybe)

I've noticed this as well.

I am 33% over the cap (87%) for fire res and experience no degen while in my hideout with RF active. My Ruby flask has the Curse Immune mod on it.

While running the map normally and using my flasks, if there is a gap in monsters, or i do not generate enough flask charges to give a 100% up-time of my Ruby flask, i start to degen (with no other debuffs other than Ele Weak on my character). This degen stops once I hit Low life and the extra 25% Fire resist kicks in from Rise of the Phoenix.

The last time this happened, I completed the map, went back to my Hideout, re-entered the map and activated RF. I was 3% over the fire res cap still. I did not degen even after using my Ruby flask and the effect ran out.

My flasks are Quicksilver (additional Movement), Silver (Bleed immune), Ruby (Curse Immune), Sulphur (Shock Immune) and Witchfire Brew.

Not sure if there's some weird interaction with the Ele Weakness map mod and flask mods that is causing the Ele Weak mod to increase in strength, but its seem to be the case, given once I hit Low Life i start to regenerate again with the extra Fire resist from ROTP.

Might eventually be related to that : https://www.pathofexile.com/forum/view-thread/2045272
And https://www.pathofexile.com/forum/view-thread/2044766

Thank for the responses. After some more mapping and paying attention, i do also get the witchfire curse bug on every map curse. I'm also 99% sure the bug i describe happens with temp chains where i can barely move at all and feels like I'm chilled+temp chains. I initially thought I was being chilled but never got the debuff icon for it.

I can pretty much avoid the bug 100% of the time if i use curse immune after witchfire. Still an annoying bug that requires a bit of micromanagement to avoid.