Hello there, @beyondbookeeping.
Thank you for joining the Community. I'd be happy to help share some insights about connecting the accounts to Online Banking.
You can disconnect both accounts to correct QuickBooks Online connection of getting your transactions from your bank. To start, I recommend checking with your bank how they send the downloaded transactions. This way, you'll be able to add or match the transactions on the correct account before disconnecting.
After that, please follow the steps below to disconnect the accounts:
- On the left pane, select Banking.
- Choose an account you want to disconnect and click on the pencil icon.
- Select Edit account info.
- In the Account window, click on Disconnect this account on save to select.
- Select Save and Close.
Once done, you can reconnect the correct account to QuickBooks Online and download the recent transactions. I've attached an article and some screenshots for additional reference:
These resources should help to get you back on track. Stay in touch if you have any other questions about connecting accounts to QuickBooks. I'll be happy to help you out. Have a great day ahead.