Resample to OHLC formed is mismatch with underlying data

Question

    quote_datetime,last
    2020-03-02 09:45:00,276.76
    2020-03-02 10:00:00,276.8
    2020-03-02 10:15:00,276.62
    2020-03-02 10:30:00,276.81
    2020-03-02 10:45:00,277