MaxSpread and MaxPrespike are protective parameters that can hinder trade entry in times of huge spreads and prespikes.
Use the MaxSpread parameter to define the maximum bid/ask spread that you are willing to accept on your trade. If the threshold is surpassed, the EA will block any signal for 500ms. After that, it will check if the spread is still above this threshold. If it is, it will wait another 500ms and check again. If the spread is smaller than your threshold, trading will be re-enabled.
MaxPrespike can hinder trade entry if a certain distance in pips/points per 2 seconds is passed. If price moves more than the MaxPrespike distance, trading will be disabled for 5s.
In order to make sure that you select the right size for these values, please read this article (-> how to select the right point size).