Closing Price errors

Hi,

I am testing a lot with alpaca but getting many error here and there both in beta and production. Today my algo was gaining good but suddenly I saw a drop in profit due to the stock ‘KLAC’. Its closing price is $325.30 . In all other platforms its closing price is $331.03. The lowest the stock went was $328.22 . How come alpaca set the price 325.30 ?