Ok, good, It must be then that when the job is saved from CAD, the operator is being prompted to accept the Oversized parts.
Once it has been split, it will not need splitting again when its time to nest, hence no prompt.
The way to force this to prompt would be for the CAM operator to select ALL the parts in Job Contents, then right click and select "Change Specification" might say "Pressure Class", simple click OK without changing anything, this will redevelop the parts, then when he nests they will require breaking down.