Let's get your invoice numbers in sequence, @usershartpm.
Let's perform the browser troubleshooting steps to resolve this unexpected behavior. Open your account using the incognito mode or a private browser. This browsing doesn’t store data and will help the page load without issues from temporary data.
If the invoice numbers are working correctly, you'll want to clear the cache to start on a clean slate. This process helps the browser to fetch the latest version of the webpage and a faster browsing experience.