I see how essential it is for you to create an invoice in QuickBooks Online, @Naomi. Allow me to help you get the best assistance for your concern.

To conduct a thorough investigation into the issues you are experiencing, particularly the problems related to the VAT box and latency, I recommend contacting our Customer Support team since they have essential tools and expertise to securely examine and assess your account and can offer comprehensive information and assistance regarding these specific concerns.

Here's how:

1. Sign in to your QuickBooks Online Account.
2. Go to the Help menu and select the Search tab.
3. Click on Contact Us.
4. Enter a brief description of your concern and select Continue.
5. Then, choose either Start a Chat or Get a Callback to start connecting with them.

For more information: Why is my QuickBooks Online slow?

Furthermore, I have included some helpful articles that provide further insights into the subject matter:

• Customise invoices, estimates, and sales receipts in QuickBooks Online.
• Set up and send progress invoices in QuickBooks Online.

If you have questions about managing your invoices or other QuickBooks-related concerns, feel free to drop a comment below, and I'll provide the necessary help.