share running config on both nexus and on IOS device for portchannel and member ports.
if config looks ok, check with mode on see if this port channel comes up?
you can use https://www.cisco.com/c/en/us/support/docs/routers/7000-series-routers/116140-config-nexus-peer-00.html
it is same for n5k.
regards,
Lovkesh
