I have set the shcluster_label on the search head cluster members after deployment. The label is also set on the deployer. Unfortunately, the distributed management console sees two cluster members with the proper label and one member with a GUID label.
This seems to mess with the "Search Head Clustering: Status and Configuration" page, even though all 3 hosts are listed under "Snapshots" only two of them are visible on "Historical Charts" and when I switch to the GUID named cluster only the missing one is visible...
OK, I edited $SPLUNK_HOME/etc/system/local/distsearch.conf, moving the problematic search head from the GUID group to the labelled group and also removed it's mention from $SPLUNK_HOME/etc/apps/splunk_management_console/local/splunk_management_console_assets.conf
This seems to have fixed the problem