The -firstMember argument is only supposed to be used for the first member, not for every member. In this case, several single machine clusters are created.
Please leave one first member server and do the following steps on the remaining servers where you have run nhJoinCluster -firstMember, so that -firstMember configuration is wiped out and you can join them into one cluster.
1. Destroy and recreate database
2. Remove $NH_HOME/sys/password.cfg file
3. Join cluster to the first member's cluster
nhJoinCluster -host <first member hostname> -useStdDac yes
Release: LHBASC99000-6.2-eHealth-Live Health Upgrade Elements