Novi AMS association customers may have noticed when going to a customer record in Quickbooks that some old, outstanding invoices that don't necessarily show up in your overdue transactions query.
By default, QuickBooks pulls data from the last 365 days. Any transactions that are older than that will need to be accessed by filtering the data to a custom date range.
On your sales transactions list, click the "filter" button and change the date range to fit your parameters.