EA behaving differently in the demo account and backtesting

[Mateus 99]

I developed a EA and it works perfecly fine when I run a backtest on it, but when I insert it on the chart using my demo account, it behaves differently.
For example: In the backtest i run it using 1 lot, but for some reason in the demo account on real time it uses 2 lots.

I didn't test it on the real account yet, only on demo (that would probably have the same results)

Any ideas why this is happening?

[Maurizio Jose Sgro]

Send a screen of how you set the parameters before starting the backtest