Welcome to the Community forum, Rock!
I can definitely help with that. It's convenient indeed to easily track the completed work on your invoices, so let's sort this out so you can add notes and attachments seamlessly.
Start by performing some troubleshooting steps to address this odd behavior. I recommend clearing the cache and deleting Intuit-specific cookies to guarantee the browser is running the program as designed. You can also switch to another compatible option to verify if it's a webpage issue.
You can also customize invoices, estimates, and sales receipts in QuickBooks Online to tailor your forms according to your needs. Another way to organize the template is by using custom fields.
Please let us know if you have any questions as you try these steps. We'll be here to address them for you.