I've got some other steps in deleting a duplicate journal entry, @kimfurry.

In addition to LorriTES suggested, you’ll want to click the Magnifying glass icon to locate and delete duplicate Journal Entry (JE). Let me guide you how to do it in your QuickBooks Online (QBO) account.

Here’s how:

1. Click the Magnifying glass icon.
2. Enter the date, amount, or transaction number you’re looking for then select the desired transaction
3. Select Advanced Search if the transaction you’re looking for does not appear in the result.
4. Adjust the filters to find the duplicate journal entry.
5. Once done, select the duplicate JE. 
6. Click More and select Delete.

You can also check this article that provides the complete details in using the Advanced feature in QBO: Search for transactions.

I also recommend consulting with your accountant to ensure the accuracy of your accounts after deleting the duplicate.

Once done, you can now reconcile your account anytime you’re ready. To guide you through the whole process smoothly, I’ve added this article for your reference: Reconcile an account in QuickBooks Online.

Please know that you’re always welcome to post anytime you have other concerns in managing your transactions in QBO. I’m more than happy to work with you. Have a great day and keep safe!