there could be several reasons causing NetFlow not to capture all traffic for specified interface. Here the couple of points to check:
- do you have both "ip flow ingress" and "ip flow egress" options of NetFlow export turned on on the router (in Orion chart Egress traffic is exactly about 10 Mbps). Which router model do you use? Can you attach NetFlow config for investigation?
- do you have options "Enable data retention for traffic on unmonitored ports" and "Allow monitoring of flows from unmanaged interfaces" turned on at NetFlow Admin page?