You have recently enabled some new probes, or new metrics within a probe, but the data is not showing up in List Designer so you cannot create a List View showing the data.
DX UIM - 23.4.0 or higher
List Designer/List Viewer
ROBOT_NIS_CACHE subject missing from hub
If the ROBOT_NIS_CACHE subject is not being transmitted from secondary hubs to the primary hub, discovery_server will not be able to consume the metric information into the database.
Ensure all hubs have ROBOT_NIS_CACHE as part of the subjects which are included in their queues.
It is sufficient to use a wildcard (asterisk) if you do not wish to specify the subjects individually.