Thanks for taking the time to share your concern about the new invoice format and turning off the Custom transaction numbers feature in QuickBooks Online (QBO), Cathy.

I understand that you want to go back to the old layouts where you are used to and I'm here to guide you on how to do it on your end. 

Before doing so, please know that the new invoice format is designed to provide a more comprehensive overview of your transactions and improve the overall experience as it's based on the majority's needs, adapting to new technology's capabilities. However, we want you to know that we're not forcing you to use it. If you feel comfortable with the previous layout and prefer not to switch to the new format, there's absolutely no obligation to do so. 

If you're currently in the new format, you can always switch back to the previous one in your QBO account. I'll show you how:
 

1. Go to +New.
2. Select Invoice.
3. At the top right of the form, select Old layout.
   
   
    

To learn more about the new invoice experience or updates, check out this link: See what’s new with estimates and invoices in QuickBooks Online.

With regard to your Custom Transaction numbers not turning off, let's go ahead and check if this is a browser-related issue by logging into your account using a private or incognito window. The system occasionally behaves strangely when the browser frequently accesses pages. It could be due to corrupted cache files in your browser.
 

When you're able to turn off the feature without it reverting back, it's safe to say that it's being caused by the browser. To rectify this, return to your regular browser and clear the cache. Sometimes, cached data can cause unexpected glitches. Clearing your browser's cache and cookies will help improve system performance.

If the same thing happens even with private browsing, let's use other supported browsers that meet the system requirements like Google Chrome, Edge, Safari, and Mozilla Firefox.

For future reference, here's an article you can visit that can guide you in recording your invoice payments in QBO: Receive invoice payment.

Keep me posted about the result by leaving your reply below. I want to ensure that this is taken care of. Take care, and I wish your business continued success.