Although total of invoices match total of payment,I can not get the system to accept it. It says total must add to zero.(although last invoice does add to zero)

Let's perform some troubleshooting solutions for you to receive payments from an invoice in QuickBooks Online (QBO), gvpropertymainte.

I've checked here on our end and there's no reported case about this one. There are times when a browser's cache data becomes full of frequent access to web pages or damaged. This causes odd behavior when receiving payments in QBO. Let's try signing in to your account using a private or incognito window to helps us confirm browser-related issues. Here's how:

• For Google Chrome browser: Ctrl + Shift + N
• For Mozilla Firefox browser: Ctrl + Shift + P
• For Safari browser: Command + Option + P

Then, try receiving invoice payment again. Here's how:

1. Tap the+ New Plus icon. 
2. Select Receive payment.
3. From the Customer dropdown, choose the name of the customer.
4. From the Payment method dropdown, select the payment method.
5. From the Deposit to dropdown, select the account you put the payment into. You can put the money directly into an account, like your transaction account, or select Undeposited Funds if you need to group the payment with others. 
6. In the Outstanding Transactions section, tap the checkbox for the invoice you're recording the payment for.
7. Enter the Reference no. and Memo if needed. This is optional.
8. Press Save and close.

If it works, go back to your regular browser and clear the cache to delete those temporarily stored files and browsing history. The overtime collection of data can create corruption, however, removing this should fix the issue. You can also use supported, up-to-date browsers to roll out the possibility of a browser-related issue. 

Feel free to visit our Sales and customers page for more insights about managing your company's income and sales transactions.

I'd like to know how you get on after trying the steps as I want to ensure this is resolved for you. Just reply to this post and I'll get back to you. Take care always.