I can help you fix the problem of saving invoices and estimates in QuickBooks Online, @JamesHumanity.
Before we proceed, I would appreciate it if you could inform me whether you are encountering an error message when attempting to save invoices and estimates.
In the meantime, I recommend performing browser troubleshooting steps.
Here's how:
You should first log into your QuickBooks Online (QBO) account using a private window. This removes cookies and browser history to prevent online tracking and ensure a clean browsing session, making it easier to navigate any websites and troubleshoot errors. For your reference, you can use the following shortcut keys:
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Safari: Command + Shift + N
Microsoft Edge: Ctrl + Shift + P
When everything works fine, it's important to ensure no more issues. If you encounter further difficulties, I recommend clearing your browser's cache, as this may aid in resolving the problem. Cached files and outdated data can sometimes impede the proper loading of a webpage. Furthermore, certain browsers have settings that can prompt the automatic reloading of pages. You can also try using a different supported browser as an alternative.