The numbers you will see there are only as good as the last time you ran an a/r aging report or statement for the client.

As it turns out, if period-end processing isn't done then the invoices and aging information doesn't move into the period buckets for reporting/dashboards. So, the period ends haven't been done for a while, but not as far as as the data that isn't appearing. So that's a bit of a mystery still, but at least we know the issue now.