BPM delegated person cannot see old pending approval expense report

Summary:

After delegate assistant to approve on behalf of manager, we found that the assistant is not able to open the expense report that are still pending approval by the manager. How can the assistant be able to access the expense reports submitted before which are still pending the manager approval?

Content (please ensure you mask any confidential information):

Manager A delegate expense report approval to assistant A, assistant A is leaving and the delegation update to assistant B.

Assistant B cannot see the pending expense report, which has not been approved by assistant A.

Version (include the version you are using, if applicable):