Unable to detect TCP using Airpcap

Good Morning,

I have the following setup for which i am sniffing in promiscuous mode (using AirPcapNx).

AP----TCP/UDP Uplink / Downlink------> Client

           PC -----> AirPcapNx (configured to sniff in the same channel at the AP client connection) .

The AirPcapNx is hosted on a Windows PC, the adapter on the windows PC is down.

If my memory serves me right i used the same setup but with MacBOOK Pro susbsituted for AirPcapNx, then i was able to sniff all the traffic.

Can't AirPcapNx detect TCP traffic. Any setting i need to be aware of.

Thanks Bharat C P