When I created background job using VF06 its creating job with name RV60SBAT with start date and time given by me. When I went and checked in SM37 there are 2 jobs with 10mins gap. One RV60SBAT and another INVOICE_Date_Time_System name. Only the second job created some invoices. The problem is not all deliveries are getting invoiced. Only some deliveries are invoiced.
I also tried creating job directly using SM36 and program SDBILLDL. It also is not creating invoices for all deliveries. When I execute in foreground using VF04 I could create invoices for all deliveries.