The right side "customization, payment options, design and scheduling" side menu opens every time I create a new invoice or edit/view an existing one. Can it be disabled?

Thanks for getting in touch with the Community, andrew134. I appreciate your detailed information.

The Manage invoice side-bar can be disabled from appearing every time you edit or create an invoice by clicking its Close (X) icon or Manage option.

With the new invoicing experience, if you leave your Manage invoice side-bar up when finished working with an invoice, it will still be up when you go to create or edit an invoice again.

Likewise, if you leave it closed each time you finish working with an invoice, it will remain closed.

I've also included a couple detailed resources about  working with invoices which may come in handy moving forward:
 

• Create & manage invoices
• See what’s new with invoices

If there's any additional questions, I'm just a post away. Have an awesome Friday!

The 'manage invoice' screen is now defaulting to opening with every invoice, even when switched off on previous occasions.  Is there a setting that needs changing?

The Manage invoice screen is one of the enhancements that are included in new invoice format, Kathy152.

For now, QuickBooks Online doesn't have any built-in options to automatically launch or close this section when creating new invoices. The program will retain the layout and settings from the last invoice that you created. This means that when you return to create a new invoice, you'll find the screen configured as you left it previously.

However, browser issues or other technical hiccups can cause the system to behave unexpectedly. Since you're experiencing unusual results or behavior while using the program, I'd like to share some general troubleshooting steps that can resolve issues like this. Let me show you how:

1. Use a private/incognito browsing session or restart your browser.
2. Clear your browser's cache.
3. Add Intuit as a trusted site.

For future reference, you can also use these articles as additional guidance when working with invoices in QuickBooks Online:

• Add An Account Summary To An Invoice In QuickBooks Online
• Create The Same Invoice For Multiple Customers In QuickBooks Online

If you need further assistance with customer invoicing or customizing your sales transactions, don't hesitate to return to our forum. We're always here to provide support and guidance.