I've just spent 3 hours typing an estimate, clicked save and send o ly to be logged out and lose all my work??

We don't want our customers inconvenienced, Dhutchison1.

It looks like you're logged out because of the time-out feature. I'd like to explain how it works.

QuickBooks Online uses a time-out function for security purposes. It helps prevent unauthorised people from accessing your account, especially when you're away from your computer. It also measures the last time you moved or clicked your mouse and used your keyboard. Once you're inactive beyond the setup time, you'll be logged out automatically.

You can use the QuickBooks Online Desktop App instead. It has a Stay Signed-in feature to remain logged in to your account. Open this link so you can begin the process. Scroll down and click the Free download button under Get the QuickBooks Mac or Windows App. 

Once it's installed, you can immediately see the shortcut icon for QBO on your desktop. Just click it and sign in using your credentials.

If there's anything else that you need, please don't hesitate to get back to this thread. We'll reply as soon as we can.