Hi there, Accounts612. Are you by any chance using a project name already assigned to that same customer? QuickBooks Online requires each project name to be unique. If you try to reuse a name for the same client, the system will prevent you from saving it. You can only use the same name for different customers.
Also, you cannot move projects, but you can delete them if there aren't any outstanding transactions. It is a built-in safeguard to keep your financial records accurate.
To keep your list organized, a great workaround is to rename your old projects. You can click Edit and add a keyword like "Finished" or "Completed", which makes it easy to differentiate them from your active work while keeping all your important financial data exactly where it belongs.

This thread remains open if you need additional help managing your QuickBooks projects.