Cant change an account on bank register?

Hi, MEF5.

I'll be more than happy to show you a way on how you can change those transactions.

You can directly open your bank register from the Chart of Accounts. Then, individually edit the transactions from there. Here's how: 

1. Go to the Accounting menu, and then select Chart of Accounts. 
2. Find the account register you want to review and then select View register from the Action column.
3. Select the appropriate transaction to expand the view.
4. Make the necessary changes.
5. When you're done, select Save.

Also, I'm adding this article that you can use as a reference in reviewing and categorizing your bank transactions: Categorize and match online bank transactions in QuickBooks Online

I'll be here to help if you have additional questions about banking. Have a good one.