I got your back, @rmrepair1. I'm here to ensure you'll be able to delete the duplicate expense in QuickBooks Online (QBO). 

Duplicate transactions usually happen when you disconnect and reconnect an account. If you updated your bank details using this method, QuickBooks will redownload your previous data. 

The income and expenses that will upload to the system will depend on the information that your bank shares. There are times a financial institution linked to QuickBooks downloads duplicate transactions. 

There are simple steps you can follow to resolve the problem. I recommend using the Exclude feature to remove duplicates from your banking. Here's how: 

1. Go to the Banking menu or Transactions menu, then select the Banking tab.
2. Select the For Review tab.
3. Select the checkbox of the transactions to exclude.
4. Select Exclude. 
   
5. You can go to the Excluded tab to remove the transaction permanently.

For more information about managing expense transactions in QBO, feel free to read this article: Enter and manage expenses in QuickBooks Online. 

You can also run the Audit log report to see all the actions you did in your QBO account. This is also helpful in case you need to recreate some deleted entries. 

I'm just around the corner to help if you have any other concerns about deleting duplicate expenses in QBO. Please don't hesitate to post a reply below. Have a good one and keep safe.