How to stop non-inventory item to be fulfilled while using Credit Hold in order management.

Hi,

We are using credit hold at shipping level for all sales orders. We've a query that while the order is on HOLD, the non-inventory / non ship-able items in the order getting "fulfilled". Due to this we are unable to cancel the orders while the orders are on HOLD.

Through fulfillment set we tried to restrict it but we couldn't succeed, since the fulfillment set is only applicable for Inventory items. Our requirement is all lines within the order should not be fulfilled whether it is inventory or non-inventory item till the order is on HOLD. Please advice how can we raise this restriction so that non-inventory items can not get fulfilled while the order is on HOLD?