Various reasons listed under the "Differences Between Summary and Detail Amounts" section.
What might cause discrepancies between summary and detail amounts in the reconciliation report?
Data modification after running the preparation process, accounting activities in the subledger or general ledger after running the preparation process, and security rules restricting data view. Data modification after running the preparation process, accounting activities in the subledger or general ledger after running the preparation process, and security rules restricting data view. Data modification after running the preparation process, accounting activities in the subledger or general ledger after running the preparation process, and security rules restricting data view.