Thanks for posting in the Community space, userralph!

If the deleted transaction is from the most recent reconciled period, you can recreate the deleted transaction. Then, manually reconcile by marking an R in the account history. 

If you want to view the information on the deleted transaction, click on the Gear Icon, and select Audit logs. Or you can view the Reconciliation report under the Reports tab and search Reconciliation report.

Here's how to manually reconcile the transaction after you've re-created it back in QuickBooks Online:

1. Click on the Accounting tab.
2. Click on Chart of Accounts.
3. Locate the bank/credit card account, and click on Account history.
4. Locate the transaction and then, locate the check mark column, click on the box to put an R to manually reconcile the transaction.
5. Click on Save.

Then, check your reconciliation page once more to verify the ending and beginning balance of the account. You may want to check these links to learn more about Reconcile an account in QuickBooks Online and Fix issues at the end of a reconciliation in QuickBooks Online.

Get back to this thread if you have more questions. We'll be sure to get back to you as soon as we can. Have a great day!