per-ip-shaper not applying properly f91g

Hello all,

i'm trying to limit how much bandwidth my user can have for downloading. i have setup a per-ip-shaper at 30mb but it seems that the limitation randomly apply at 10-15mb instead. from what i can find online this seems to be the proper way to use it? i have set the web facing interface max bandwidth properly and can't think of why it wouldn't match the speed i set, any idea?