Just look in the manual: "Max DD - Maximum drawdown during the test period, in account currency units and in percent from the gross profit.".

Reinvesting capital will of course affect the gross profit, which renders the max DD relatively meaningless. It depends then not anymore on the strategy performance, but on your reinvesting. For knowing the drawdown of your strategy, disable reinvesting.

"PnL" means "Profit and Loss", not "Profit plus Capital".