Good to hear from you today, tinap1.
To post and receive the entire invoice payment amount, you might want to delete and recreate the payment transaction. Let me show you how.
To delete the payment:
- Locate and open the invoice.
- On the invoice screen, press CTRL + H on your keyboard altogether.
- Under Transaction History - Invoice window, double-click the Payment to open the transaction.

- Click Delete and hit OK.

- Click Save & Close.
Once deleted, let's receive the payment again. Here's how:
- Click Customers at the top menu bar and choose Receive Payments.
- Select a customer.
- Ensure that the applied amount is correct.

- Hit Save & Close.
To help guide you more in receiving and recording invoice payments in QuickBooks, you can go through these articles:
Record an invoice payment
Deposit payments into the Undeposited Funds account in QuickBooks Desktop
If there's anything else I can help you with, please let me know. I'd be more than willing to lend you a hand.