Hi,@NumbersByNelson.
 

Navigating banking tasks in QuickBooks Online can occasionally be challenging. I'm here to offer the information you need to address your questions.

Before linking a bank account in QuickBooks, please make sure that when posting a payment, it should also be connected to the chosen account. 

Please note that it is not allowed to link both parent and subaccounts to avoid discrepancy issues.

And also, it should base it all on the bank statement when fixing what's not balanced in the account.

For detailed instructions on connecting your sub-account, please refer to the article:

Connect bank and credit card accounts to QuickBooks Online

In your additional question about your journal entry that you made and tried to correct the balance, I can see that you tried to do a reconciliation. Please do reach out to a accountant to fix your Bank Reconciliation, and also here's a helpful guide for you to check and fix the reconciliation issue: 

Fix Issue at the end of a reconciliation

I'm available around the clock to provide a timely response if you have any other questions about handing projects or sales transaction. Simply hit the Reply button below.