Hi annie-chen,
Are you trying to match a bank transaction to multiple transactions in QuickBooks Online? If so, you can click on the Find match option. This way, QuickBooks will display all possible matched transactions for it.
If you received an error message while matching a transaction, please check out this article for the troubleshooting steps: Fix Online Banking Errors in QuickBooks Online.
Let me know if you have any questions. We're here to help.