A client has OE invoices in their Current list back to 1999. It looks like every invoice for the past 16 years is still in Current.

Their Day End settings are "Purge from current" = 30 and "Purge from History" = 999 days. They run Day End regularly and Orders are properly being purged from Current as part of Day End. Credit Notes have a similar issue though they only date back to 2008.

Data Integrity Check is clear.

What factors does Day End consider when purging Invoices from Current?

OE 9.2. Thank you.