Thank you for posting in the Community! Let's take a look at your account to check on a setting that could affect your invoices in this way.
While logged into your QuickBooks Online account:
Go to the Invoicing tab on the left menu.
Along the top, click on Products and Services.
Select Edit to the right of the products/services that you use on those invoices.
There is a field for the category and the income account. If the income account matches the incorrect one that you're seeing on invoices, you can edit it here to reflect the correct one. If the income account does look correct, but your invoices still aren't, reach out back to me here and we can continue to troubleshoot!