There should be a host name between the ":" and where the red circle is.
If I go to the child node itself and not "All", the screen graphs show the HOSTNAMES in the title. But if I select "All" and go to screens the HOSTNAMES are skipped and looks like this in the graph titles:
NODE_NAME: NO_HOSTNAME: GRAPH_NAME
^------- This is missing
To see the issue you have to have "All" selected for nodes when viewing the screens with graph elements.