After upgrading DX UIM to 23.4.5 and upgrading the probes to the latest versions, you may notice that new items have appeared in the Operator Console Inventory.
All of them have the monitored_by field empty, and when checked in the database, they seem to originate from nis_cache.
It looks like the new entries were pulled from nis_cache, despite the fact that the items were removed/decommissioned in the past.
DX UIM 23.4.x
The robots/devices were not removed from the OC using the DEEP clean option.
If such an issue has already happened, it can be resolved by cleaning the niscache and removing those entries from the inventory. In order to prevent such a situation from happening in the future, please use the "deep clean" option while removing/decommissioning devices from the OC.