Symptoms:
NSX controller stuck in Waiting to join cluster and is in a disconnected state.
VMware NSX for vSphere 6.3.x
This issue occurs because the same IP address has been configured for eth0 and breth0 interfaces of the controller while the controller is coming up.
You can verify this by running the show network interface command on the NSX controller.
This issue is resolved in VMware NSX for vSphere 6.4.0,
To work around this issue if you do not want to upgrade, contact Broadcom Support and reference this KB article.