Welcome and thanks for joining the Community, @akprek.
I can help walk you through correcting the posting account for the invoice payments in QuickBooks Online (QBO).
You can easily change the payment's posting account by editing them the register. Let me show you how:
1. Go to the Accounting menu at left pane, then Chart of Accounts.2. Click View Register under Action column on the account where the payments are incorrectly posted.
3. Select the payment, then Edit.
4. On the Deposit to section, choose the correct account, then Save and close.
That should do it. I'm also including an additional article that tackles recording customer payment for future reference.
Please let me know how it goes or if you need further assistance. I'd be glad to answer them. Have a wonderful rest of the day!