How can I fix a reconciliation that was correct then someone messed it up

We can recreate those deleted transactions, @stayinsimpleservices. I'll guide you through the process.

You can use the Audit log to view the deleted transactions. Here's how:

1. Go to the Gear icon and select the Audit log.
   
    
2. Choose the appropriate option from the User and Date Changed drop-down lists.
3. From the Events drop-down menu, select Deleted/Voided transactions.
4. Click on View to see the details of every transaction.

Otherwise, If anyone has made the change that affects your beginning balance, you'll get a message before you start reconciling. You can select the We can help you fix it link to open a discrepancy report. You'll want to use it to decide if and how to make the changes.

Once done, you can recreate the transactions exactly as they appear on your Audit Log or from the Reconciliation discrepancy report.

Here's how: 

1. Click the + New button and select the correct form (invoice, sales receipt, expense, etc).
2. Fill out the form and select Save and close.
3. Go to the Gear icon, then choose Chart of accounts.
4. Locate the account that you put the transaction into and select View register.
5. Find the transaction and select it to expand the view.
6. Select the box in the checkmark column until you see an R. This manually reconciles the transaction.
7. Once done, tap Save. 

Moreover, you can open the discrepancy report if you still see an alert the next time you reconcile. The deleted transaction may still be on the list, but the difference should be $0.00. It won't affect your reconciliation.

After you review everything on the discrepancy report, the Total Discrepancy Difference on the report should be US $0.00. Recheck QuickBooks' beginning balance and ensure the beginning balance on your bank statement needs to match it. Select Resume reconciling to continue reconciling.

As further help in correcting your beginning balance for the current month, let me add this article: Fix issues for accounts you've reconciled in the past in QuickBooks Online.

Let me add this article as a guide in printing and viewing your reconciliation report: How do I view, print, or export a reconciliation report?

I'm more than willing to help if you have any other concerns with fixing reconciliation issues in QuickBooks Online. I'll ensure your needs are taken care of.