Scheduling Margin Key is lost when using MILL_OC

I’m using transaction MILL_OC to convert a bunch of planned orders into a single Mill Products Production Order.

The Scheduling Margin Key is missing from the Production Order.   If I create a Production Order using CO02 the Scheduling Margin Key copies to the Production Order.

Any idea why the Scheduling Margin Key does not copy into the combined Production Order when using MILL_OC?  Thank you very much!