KANBAN signal lock not working with PKBC

Hi,

I have implemented KANBAN for a client and for their internally procured material I am using planned order w/MRP.   However, they are using wedge scanners to change the status of these materials in PKBC.   The problem is that they are able change the status regardless of the signal lock controls when I expected an error message as the one  get when I try to change the status from PK13N.   But instead the system processes the status change.

This is causing serious problems as we designed the process to have this safeguard implemented, but it is not working and just yesterday a user managed to cycle the same KANBAN ID 8 times before it finally moved to its final location.

Any help would be greatly appreciated.

Thanks

Adam