I look at the code and in the test and cannot see a error. Please give an example what do you think is wrong.

If it is a bug, I'll fix it for minutes.

Edit:

The Level indicator is among the input parameters of the expert, however it participates in the signal formula only if the trading logic requires Level.

For example, the Level is taken into account with these logical rules:

            "Stochastic is higher than the Level line",
            "Stochastic is lower than the Level line",
            "Stochastic crosses the Level line upward",
            "Stochastic crosses the Level line downward",

The level is ignored with these rules:

            "Stochastic rises",
            "Stochastic falls",
            "Stochastic changes its direction upward",
            "Stochastic changes its direction downward",

However, if you think there is a bug, please report.