Testing by a QueryPlus user showed that the Policy Total Invoice Amount field was including more data - and Invoices, apparently - than desired.
The extra data was found to be coming from 'On-Account Invoices', which, not being part of the normal billing activities of a Policy, should not be included in the calculation of this field. They are now filtered out.
Also, 2 new fields have been added, which break down the invoice data:
Policy Total Direct Bill Invoice Amount
Policy Total Agency Bill Invoice Amount
These fields return just what they say, and the sum of these 2 fields will always equal the amount in Policy Total Invoice Amount......
now that the pesky On-Account Invoices have been filtered out.