Ariba: OC not reflecting in S4

Hi Team,

I americium facing 1 contented successful Ariba Guided buying.

In my task we are implementing GB,PO is getting created(PR-->PO successful GB), erstwhile we bash OC it is not reflecting backmost successful S4 successful confirmations tab.what could beryllium the reason?

The confirmation power cardinal tract is empty.Tried manually selecting 'Confirmation-001' and submitting OC,still OC not showing successful the confirmations tab.No IDOCS generated.