Hello Edu,
this backtest looks bad. When you optimize in EA Studio, you have an acceptance criteria. Try to remove it, and do the optimization. This way you will see if the issue is there. If it passes, than try to make the acceptance criteria not so strict.
The Monte Carlo itself is the robustness test for over optimization. If it fails, it means that the strategy is probably over-optimized.
Another old method to see if a strategy is over optimized is to change manually some of the parameters in the indicators. If you see huge difference in the equity, this is also a sign that the strategy is over-optimized.
Have a beautiful weekend too!
Petko A