Only when Payments are posted in Adagio Payables is the 'YTD 1099' amount field updated. Posted Invoices have no relevance to this 1099 statistic. And only after the option is enabled - it will not automatically be populated with the YTD Payments amount when you first turn it on.

Generally speaking, the YTD 1099 amount should equal the YTD Payments statistic.

If the amount in the YTD 1099 field for the vendor is 0 or some other value you do not believe to be correct, you can edit it, with the instructions provided previously. Should this be necessary to edit for a lot of vendors, these values can be imported using the Import Vendors process.