Trend first: follow the trend, do not trade against the trend, even if there is a SZ or DZ. Unless your have other tools to confirm the trade, like time&space, scalping trade, price patterns, etc.
XAGUSD is still in an uptrend, so buy at the DZ is a correct trade. But since it's forming the "right shoulder" as XAUUSD does, sell at the current Supply Zone is also worth trading. Got it?