Spread has no impact on stop loss. It triggers when the relevant price (bid or ask) reaches the stop loss. It does not trigger when the chart price (usually bid) reaches it.
Slippage is normal and the slippage here isn’t huge. If I plot a tick chart, you can see how far the price is moving each tick. It’s not the same and it doesn’t fill in the candles smoothly. ie the green dashes have different distances between each line to the next and previous.
