Hi Kevin, thank you for answering. 

In the question, I mistakenly inverted the kind of items that were backordered incorrectly. The only ones that were correctly calculated were the ones that were partially invoiced. All the others had an invoice backorder of zero, and then the Sales Order lines were deleted.

I checked the posted invoice as you told me,  and it is getting zero in BO if nothing is shipped. Then the SO line if deleted, but just because the BO column is not being calculated properly.

Why could this be happening?

Hi Kevin, thank you for answering. 

In the question, I mistakenly inverted the kind of items that were backordered incorrectly. The only ones that were correctly calculated were the ones that were partially invoiced. All the others had an invoice backorder of zero, and then the Sales Order lines were deleted.

I checked the posted invoice as you told me,  and it is getting zero in BO if nothing is shipped. Then the SO line if deleted, but just because the BO column is not being calculated properly.

Why could this be happening?

We've seen that when importing invoices using VI, where the source file doesn't contain all lines.  Are you creating invoices using some sort of import process?

We are not using VI for invoices, we are using Scanforce for picking and shipping, but we are doing it since a very long time ago. The new thing here is a VI but for sales order. Can you please check if there is something wrong with it?

Look at your invoice creation process for how BO quantity is being set incorrectly.  If the invoices are created incorrectly using ScanForce, ask for their help in troubleshooting.