Supplier punchout through Oracle Business network - Session timeout

Summary:

We have setup a Punchout with one of the suppliers using the source as Oracle Business network. Issues when returning back to SSP when the time taken is more than a minute or so

Content (required):

We have setup a Punchout with one of the suppliers (Complete Office Supplies COS) using the source as Oracle Business network.

The punchout works fine and if the user selects items from the supplier site and returns the items in the cart within a minute or so , then there is no issue and items are returned back to Self Procurement.

However if the time taken is more , then once the user selects the option to return the items , we just get a blank page.