Aggregate function returning incorrect results

Hi,

We have a list page that displays all subscriptions for a service. Within the list we want to display the most recent case that was raised against that subscription and its status. We have used an aggregate (maximum value) against the “Subscription object - Case object” relationship, case type field. 99% of the time this works. However we have found that if there is a case in the subscriptions history that has a status “abandoned” this case is returned by default, regardless of any more recent cases.

Whilst I recognise the need for us to clear out the abandoned cases, I wondered if this points to a fault in the way that the Aggregate function is operating? Has anyone else found a similar issue? If so, how did you resolve it?