Why doesn’t 1 say close price always match the close price for the last 30 minute candle

I’ve noticed in historical NYSE data on trading view (using paid NYSE data) that the close price for 1 day candles often doesn’t match the close price for the last 30 minute candle. If close price should just be the price at which the last transaction was executed, why don’t these always match? Is it a problem in the data?