Visible slippage impact negatively affects custom trading strategies in cTrader

Greetings,

I am professionally implementing my own strategies in cTrader API.

The problem is as you can spot below in one backtest/live brokerage (FxPro) I am experiencing different behavior (profits) than another one (like Spotware (Hedging)) (losses) for exactly the same day period and minute resolution. Also, leverage settings seem the same, alongside the received data server tick data (accurate).

Is the issue due to slippage between different brokerages in cTrader? Is some setting I should consider in the robot model? Another generic setting in the experiment environment?

Thanks & Regards