Approval routes (F43008 - Approval Level) audit track

Hi,

We did a proper setup for approval routes and able to approve correctly till yesterday.   Today approver is unable to see list of OP/OR orders waiting in his queue for approval.  When approver delegated authority to other user he (other user) is able to see the PO's in his queue and able to approve.  Why first approver is not able to see them and the same was available in second approver queue?.  Also can we see audit track of approvar like when approver was setup, when he got authority to approve, delegation information, and incase of any changes made to approval