How to stop packaging when serial numbers are not added to the deliveries?

WM Experts,

During the picking/packing process in the warehouse for serial number marked articles, previously the packing function was stopped unless the serial numbers were added to the deliveries.

Now only the goods issue is prevented and by then it is too late. Something has changed in SAP.

We need to have the process corrected to be like it was before, or a function similar to the bin location check number that requires S/N input prior to confirmation.

Kindly help.