BOM main item not getting copied in delivery

Hi

For a BOM item in a sales order, in the delivery the main item is not getting copied. I got a solution saying the problem is with the delivery group in item category or with the stock availability. But with the same material, i tried to create an order for a different order type. Ther was no issue and the delivery got created with all the items. The problem is with a particular order type only.

Can somebody help me on this issue.