Thanks for joining the thread, @tiawhit.

Once we switch back to the old invoice layout, we still have the option to go back to the new format. All you have to do is simply open again the sales transaction and click Try the new invoices from the upper right corner of the screen. Then, select again Try new invoice.
 

Please take note that switching from a business or accountant view won't affect the invoice layout. I'd also appreciate it if you can share a screenshot with us. That way, we can review it and provide you with the right solution. 

In the meantime, let's open your account in private to check if the issue is cache-related. There are times that too much cache build-up can cause unexpected behavior with the product. This can be the reason why you're unable to see this option. You can press the following shortcut keys to access this mode:

• Ctrl + Shift + N (Google Chrome).
• Ctrl + Shift + P (Firefox).
• Control + Option + P (Safari).

If you're able to alter your preferences, then let's clear the cache in your web browser or try using a different supported browser. It could be a temporary issue with QuickBooks and the current browser that you use.
 

Moreover, we can freely switch back from old to new preferences at any time. Just click Old layout or Try the new invoices from the invoice window and you can continue with your business. 

You can also check out this article for more info: See what’s new with estimates and invoices in QuickBooks Online.
 

Please let me know if you need further clarification about the new experience. I'm always to provide answers to your QuickBooks queries. Have a nice day!