Arcane Master's Lightning Meteor Combo Proc Bug

[foofins]

Is this passive skill bugged? The 80% chance to trigger chain lightning only works on Plain of Ida, Kobolds, and the training dummies in Prontera. I posted this on the ROM subreddit and somebody from the Global server said that for him, it procs everywhere. I already tried making a new AM using criatura and I still had the same results. I also tried offline farming and it still doesn't work. What's wrong with this?