why are transactions from one bank account showing up in another bank account?

I appreciate the time and effort you put into reaching out and providing detailed information, Park. I will help you check your payroll preferences and verify if the correct bank account is assigned.
 

Here's how:

1. Click the Gear icon and choose the Payroll setting.
2. Go to the Accounting section. Then, click the pencil icon to expand the page.
3. Set up the appropriate account for each payroll preference.
4. Then, select Continue once done.

Additionally, I have this helpful article that explains how to determine what account type you can use for your payroll transactions. It also covers how to change past transactions after updating your account: Change your accounting preferences in QuickBooks Online Payroll.

Once everything is all set, reconcile your accounts. I'd recommend doing this every month to help monitor your income and expense transactions and detect possible errors accordingly. You may want to check out this article as your reference in doing and fixing reconciliations in QBO: Learn the reconcile workflow in QuickBooks.

I'm all ears if you have other banking concerns or questions about managing your accounts and If you have any other banking concerns or questions about managing your accounts and transactions in QuickBooks Online, feel free to leave a comment below, and I'll be happy to help!