SRM Create Central Confirmation result "No documents found"

Hi Experts

We are on SRM 7.2  Classic Scenario. Users  particularly Central Confirmation User are not been able to post confirmations in SRM.

These users have all the roles. mainly these are Key Users.

When they use Advanced Search/Create confirmation button and search for a particular PO to post confirmation the system throws the message "No documents found for the search criteria"

Normal Users are able to search the PO and can continue to do the confirmation.

I have checked all the roles in SRM and ECC. All are fine.

Please advice on this.

Regards

Ajit