NSX 4.x
This is currently impacting 4.0.x release and will be fixed in a future release.
Workaround:
Restart Envoy, confirm it is now running, and validate that the node can be reached now via IP/FQDN when browsing to it.
/etc/init.d/envoy restart
/etc/init.d/envoy status
Running curl -kv https://<FQDN/IP> against the impacted will now show the updated certificate and the UI should come UP.