There isn’t a “save button” when you are working in a file. You have to go into Save, correct? If so, is it auto saving so you don’t lose anything just in case a system crash?
You need to manually Save the file. We recommend to save your file every 15 minutes by going to menu File-Save. The Auto Save feature will not overwrite your file, in case of a crash you can recover your file by going to menu File-Open-Open Unsaved Project.