Hey there, SJLES PTA.

Here are some of the causes why your reconciliation ending balance is wrong:

• An incorrect ending balance at the start of the reconciliation.
• Missing or duplicate transactions in QuickBooks.
• Someone entered transactions into QuickBooks that hasn't cleared your bank yet.
• Duplicate transactions.

You might want to verify the pending deposit if it's part of your May statements. Once verified, you'll need to redo the reconciliation process to ensure your books are accurate. On the same links, you'll find detailed steps on how to resolve balance issues in the program.

Undo a client’s reconciliation in QuickBooks Online Accountant.

Fix issues at the end of a reconciliation in QuickBooks Online.

Additionally, you might want to check this guide on how to reconcile the accounts properly: Learn the reconcile workflow in QuickBooks.

Feel free to drop me a reply below if there's anything else I can do to help you. I'll be standing by to provide additional assistance.