Why does my node show Outgoing and Incoming data but I have zero SWRM pending this period?

Network communication is not considered data flowing through the network.

You earn SWRM coin for data that you deliver to other peers and end users. While the graph may show small amounts of incoming and outgoing data (typically less than 0.1 Mbps), this is considered network communication and is not rewarded in SWRM coin.