Fulfillment Workbench - error message with backflush materials

We are in the process of implementing Fulfillment Workbench. For the most part it’s working as we had hoped for allocating parts to orders/jobs.

One quirk seems to be that it generates an error message for backflushed parts, and after you allocate, the message show
59 Demand record(s) allocated
41 Demand record(s) selected for picking
18 Demand record(s) with picking errors
42 Demand record(s) submitted for picking

The 18 records with picking errors are all backflushed parts. We know that backflushed parts do not need to be picked, it just seems confusing that a picking error message is generated and it can be confusing to the folks doing the processing.

Has anyone else experienced this and found a way around it?