I am not sure what node you are talking about and what method you are using to poll the node, is it agent based or agentless (SNMP, WMI)? What version of SolarWinds Orion are you running on.
But below link will provide all the details that you are looking for.
https://documentation.solarwinds.com/en/Success_Center/orionplatform/content/core-calculate-node-status.htm
Hope it helps.
Nodes can be in this state for a number of reasons. You may be using enhanced node status which you can learn more about here https://thwack.solarwinds.com/resources/b/product-blog/posts/orion-platform-2019-2---enhanced-node-status