Thanks for your comments!
We take note on this and will improve Drawdown calculation for all periods.
Currently, DARWIN's header shows the most accurate value of Drawdown (I still reckon it doesn't show -22%, but -20%).
On the other hand, period drawdown (the one you point out) is based on the chart and thus, not precise when you zoom in.
I understand probably this is not enough for some of you, but I want to make clear that we hear you and take note on everything that must be improved.