NPM not accurately reports data

Hi im in a situation wherein i need to monitor a specific host's bandwidth usage.

Im currently using "networkx" to see the hourly consumption of the said host.
between 13:00 - 13:59 - this host has consumed 2.41GB.

At the same time, the switch where this host is connected is also sending netflow data to solarwind's NPM. but it's appearing to be not on par with the "networkx" software result.

its reporting only 189.7Mb max. I was expecting to see the same value with the "networkx"

Can someone explain what am i missing here?