The issue we are experiencing is that the Settings page "Indexer Clustering" on our Indexing Cluster master is misreporting search heads as Down in the Status Column of the Search Heads Tab.
If this is the issue on the Search Head you need to set
$SPLUNK_HOME/etc/system/local/server.conf
[clustering]
generation_poll_interval = 120
After making the chnage restart the Splunk service for Search head.