iSupplier - Supplier initiated changes routed to requester are not getting routed to buyer for PO ap

In Purchasing there is an option to route the Supplier initiated PO changes on the iSupplier portal to the Requisitioner (Requester). The option is available under Setup -> Tolerances and Routings -> Supplier Change Order. The routing to requester can be enabled for Promise date, scheduled qty, and price changes on the POs. We wanted to use this functionality as our business process requires requester approving the changes on the requisition followed by buyer approving the changes on the PO. When we enabled this routing, the changes are getting routed to requester and going through the requisition hierarchy as intended and once the requisition change has been approved the PO is also getting automatically approved and the buyer is just getting and FYI email that the PO has been approved. This does not align with our current business process as we are expecting the buyer to receive a PO change pending notificaiton so that they can act (approve/reject) on this notification. Also as per the metalink