When using the CMDB task Inventory Clean Up, it is configured to check for (at the least) a Retired computer Status. An inclusion filter is configured that lists the Retired computers to clean up. When the task runs, however, the computers still retain inventory data.
Incorrect configuration of task.
There are two issues with this scenario:
Filters generally cannot contain Retired computers. It is unlikely, therefore that the filter that is used actually has the computer or if it does, it's not listed as Retired on it. This could indicate stale data on the filter. Manually inspect the filter and update its data to ensure that it includes the correct computers before using this with any task.
If the task is set to check for Retired computers, it therefore cannot use an inclusion filter, as the filter itself cannot include Retired computers.
The correct way to run this task to check for Retired computers is to not use an inclusion filter. This would then check all computers, based on the selected Status types of the task. If there are certain computers that are desired to not be evaluated, use an exclusion filter to remove these from being processed.