Volume Problem

Hello TradingView Community, I'm posting this in hopes one of y'all have answers. I was attempting to make my own VWAP based on one minute data since it's the best we can do and I stumbled across this when I noticed the values were abnormally low. For some reason a cumulative day's worth of 1minute volume is not equal to the actual day's volume. Its significantly lower. If anyone has any idea why or if I made an error in my script can point it out to me I would greatly appreciate it, thank you.