Flatlines for node_network_receive_bytes

Hey all,
I’m trying to set up a graph of network traffic on interface eth2 of a Linux host which has node_exporter running. I can see the metrics at host:9100, and see that node_network_receive_bytes exists for the interface:

node_network_transmit_packets{device="eth2"} 6.12491237e+08

Next I set up a panel and try to display a graph of that interface thusly: node_network_receive_bytes{device="eth2",instance="myhost.mydomain.com:9100"}.

As expected, I see a single line increasing in value across time. Makes sense.
Now I wish to plot the mean value at say, 10s intervals using a graph visualization.

I’ve tried several permutations but must be missing something, as I always get No Data Points. My latest attempts are: