My understanding is that index options are cash-settled, if expired in the money the option will be automatically exercised and the multiplier * difference between Strike and settlement price should be my profit. Basically, my question is that why isn't that cash-settled part treated as profit? 

Below is an example, in the period, I have only got one trade-in below strategy.  It buys 2 pieces of identical put option and holds till expiry. And they did expire in the money and got automatically exercised. With a net loss of 320$ which is equal to the premium I paid, my equity increased by 182$, which to me, it means that the cash settlement is not treated as profit. Is this by design? If so, is there any way I can set that cash obtained as profit as well?