I compared with a node that was added through the GUI, and there, the native pollers are attached to the node, for the ones added through the SDK, they are not. When I explicitly add these, the nodes seem to be monitored as expected. (Only the SysObjectID remains blank)
N.Status.ICMP.Native
N.Status.SNMP.Native
N.ResponseTime.ICMP.Native
N.ResponseTime.SNMP.Native
Any idea why these native pollers are not there, or should I always add them when using the SDK?