After reviewing a closed drawer and marking it as Approved, the drawer seems to be missing from the list that appears under Financials > Approve closed drawers. The drawer was not included in any deposit process, and the transactions associated with the closed drawer do not have any deposit number associated to them.
This issue can occur when the drawer in question contains a refund for a transaction that was originally made online. In Altru when a transaction that was made online is refunded that refunded transaction appears in the user's drawer. When the deposit process is ran that refunded transaction can be pulled into the process even though the other transactions in that drawer are not pulled into the deposit process. When one transaction from a drawer is pulled into the deposit process the entire drawer will be removed from the approved closed drawer screen.
To fully resolve the issue rerun your deposit process. Although the approved closed drawer is missing from the list, its transactions will likely be pulled into the next deposit that is run, provided they meet the criteria of the 'deposits to be created' settings.