It is recommended that you use 'internet Connection Sharing' (ICS) instead of NIC for all RNDIS based tethering.
However in order to debug the NIC mode, please read below:
1. Verify that the UE has established a Packet Data Protocol Context (PDP context) over the air and that RNDIS based Internet tethering is enabled. Some UE's may not assign an IP address to the RNDIS/local area connection on the laptop, until a PDP context has been established
2. Verify that your local area connection shows its status as 'connected' and that local area connection status properties show an assigned IP address/ Gateway Ip. Some UE's may at some point partially lose connectivity with the RNDIS adapter, with the adapter showing its connection status as 'limited connectivity'. In such a case, the RNDIS adapter will show its assigned IP address / Gateway as blank.
3. When observing limited connectivity, unplug the USB cable, power cycle the UE, plug the USB cable back in and enable tethering on the UE