When this happens, it can be one of 4 things:
Your code had syntax errors in it, so it does not save. This is visible when you see red errors on the screen.
Your internet connection is unstable or offline and your code editor can't connect to our servers to save. Try testing your internet connection.
You have multiple projects of the same type and have opened the incorrect project.
You have multiple editors open. Check your other open tabs in your web browser or any other windows you may have open.
Please reach out to us with any further questions or concerns! 👍