Doryani's Prototype not correctly reducing some monsters resistances

I have noticed after playing around with a build utilizing doryani's prototype that certain monsters are not affected by the unique modifier on the armor:

Nearby Enemies have Lightning Resistance equal to yours

having the armor equipped while also having lower than 0 lightning resistance changes the tag below a monsters name to "vulnerable to lightning", however it does not seem to affect everything, mainly totem based monsters.

here's a video showing the issue, the first clip is how it looks when its correctly applied to a monster, the second and third are clips of monsters that don't seem to be affected. third clip shows current resistance value as well as the chest being equipped

https://www.youtube.com/watch?v=1ZrrZbeThMc

this seems to be unique to the body armor, "nearby enemies.." effects on helmets seem to apply correctly to the same bosses shown in the video

to add to the initial post, it also does not seem to affect the statue type mobs in the ultimatum league mechanic as well