In S4 HANA- BOP Job does not update certain SO type

Hi Experts,

System : S/4 HANA 1709 ( There is no APO involved)

We are experiencing an issue in BOP (back order processing) jobs which does not update confirmation for certain sales orders .The issue has been observed only for order type which has 'Indicator field set up with value 'B-Delivery order' in the SO order type config.

can you pls share what is the usage of this field? why BOP does not include these orders.

Any additional info on this subject would be helpful.

Appreciate your reply.

Thanks