I'm a total noob on gold trades, so my siganl opened a short XAUUSD trade.

My signal's open and close price are as below:
1300.52 1307.71(SL)

My open and close price:
1300.35 1308.07

Now I'm very confused because I have set my slippage to 2 pips but still the trade was opened with 17 pips difference? Also on my MT4 terminal it says the trade hit SL(1307.71) but the close price was 1308.07 not the SL price.

I think it might be a broker thing where ICM has very different price than other brokers?

Does anyone have any experience with this?