Thanks for joining this thread, @CharlotteP. I’d be glad to help you resolve the reconciliation differences in QuickBooks Online.

Since your ending and opening balance are correct when reconciling, I recommend checking your bank statement. Make edits as needed, and ensure you’ve recorded all transactions.

In some cases, the reason for this difference amount is a duplicate transaction. If there is, then you can delete it.

In addition, I've got this helpful resource to help you fix issues at the end of a reconciliation.

To know more about reconciliation in QuickBooks Online, check these out:
Reconcile an account in QuickBooks Online.
Undo or remove transactions from reconciliations in QuickBooks Online.

Stay in touch if you have any other questions or concerns about fixing reconciliation issues. I’ll be right here to answer them for you. Enjoy the rest of the day.