In iExpense Expense Export, how is supplier site chosen?

We're have a problem with two contingent worker/suppliers when we run the Expense Export.  The each only have one active supplier site, the home site.   They have a provisional site, but it is inactive and was inactive at the time the expense report was created.  However, when running the export, it wants to use or at least create the provisional site and it fails.  Here is a snippet from the log:

Get Vendor Info when vendor id is known

Get Vendor Site Info for Employee when vendor site id is not known

Creating a vendor site (AP_VENDOR_PUB_PKG.create_vendor_site())