Position Sizing & Commissions

Hi traders,

found a problem when trying to apply fixed fractional position sizing on my strategy.

In Performance Report (Trades) I see correct Qty in no. of contracts for each trade. While I start with 1 contract and finish with approx. 30 contracts, commissions calculated in report are as if I traded only 1 contract all the time.
Why commission are not multiplied by Qty automatically? I would be happy to pay $3.6 for 30 contracts traded but unfortunately ...

Thanks