NI Probability check with Cast spell on condition

I've recently started creating my own items using NearInfinity, things have been working fine for me until now.
I'm trying to use "Cast spell on condition (232)" on an armor piece in BGEE + SoD, my problem here is that the effect triggers ALL THE TIME even with a 10% Probability.

So i was wondering, am i doing something wrong or is this function somehow hardcoded to not take into consideration the Probability parameter ?