The node health API does not return true until the second node is started, but NSX Administration Guide recommends users to confirm that the node health API return true.
GET /api/v1/reverse-proxy/node/health
Make sure the node health API returns healthy: true before you proceed to the next node.
Shut Down and Power On the NSX Manager Cluster
NSX 4.1.2.4
Until the second node is started, the node health API does not return true.
Start the second node some time after the first node is booted.