I'm here to help figure out what's happening to your estimate page in QBO. While we don't have any issues reported on this, it's possible that this is a browser-related problem. Did you already try using other browsers before? If not, let's try attempting using a private browser first to verify if this could be the case.
First, you'll need to log out and then log back in using the steps below based on the browser you're using:
Chrome - press Ctrl+Shift+N
Internet Explorer or Firefox - press Ctrl+Shift+P
Safari-hold down Command+Shift+N
Then let's go check if you can work on your estimate without any problems. If it works, you'll need to go back to your previous browser and clear your cache to clean its history. Sometimes, this stored data can create errors too. If you continue to have issues, consider trying other browser or even another computer to ensure the issue is not with the web page.
If it still won't work, I'd suggest contacting our Online Care Support to dig in deeper why you keep having this issue while working with your estimate. They'll be able to pull up your account in a secure environment and check further with the help of their tools.