I will feel the same way if something isn't working properly, @CC-Bene.
Typically, once you select a particular font size for an invoice, it should display the exact dimensions accordingly. If the issue persists after doing the troubleshooting steps, I suggest contacting our support team directly. They have the tools to check your account in a safe environment, and they can help find the root cause of your issue and find a fix.
Here's how you can reach them:
- Sign in to your QuickBooks Online company.
- Select the Help (?) menu.
- Choose the Assistant tab.
- Click the Talk to a human option.
- Select Get help from a human.
- Click either Chat with us or Have us call you button.
Moreover, let me share this resource to help you personalize your invoices in QuickBooks: Customize sales forms.
Leave a comment below if you have additional questions about managing your invoices. The Community and I will be around to help you. Keep safe and healthy always.