Perhaps the nodes will be detected earlier, if you enter the IP's of the 21 detected nodes in the config as nhz.wellKnownPeers.
All my nodes are interconnected and every node's config file contains other 31 IP in option in nhz.wellKnownPeers.
For example, IP 104.194.247.227 is not deceted where 104.194.247.229,230,231,232....all are getting paid! Strange!
Seem someone has 'increase' size of 'maximum node' value of 'nodecheck' script of HZ explorar. All my IP range 104.194.247.227-254 shows online!
Cool to know...