Recently one of the Read has question that they have define Freight Item with attributes
Shippable = YES and
Transactable = NO
and added this freight item in SHIPSET with the regular Shippable and Transactable items.
With this setup expectations are - Both the Regular and Freight Item should be Shipped together , but actually regular item got shipped without the Freight item ( even when both are part of same shipset).
Please Note that ,a ship set for non-transactable delivery lines is not validated during pick release because the item(s) are not picked from inventory. Only shippable / stockable / transactable items will be forced to ship at the same time when all lines are on the same ship set .
Thus it is not a good idea to out the Transactable and not transactable items in same Ship set.
Hope that helps.