How can I get the Node Details updated with new DNS information without removing the node and adding it back in NPM?
You should be able to rediscover the node from either the Node management page or the node details page. As long as the DNS change has propagated to the DNS server NPM is using, it should update.
That did it one server(poller) was not configured correctly with the DNS setting once fixed all nodes rediscovered with proper FQDN's
