There are a couple of reasons as to why your progress might not have saved:
Internet connection interruption - if your device lost connection to the internet while you were completing the course your progress also will have been lost. We recommend not using mobile data when completing a course; ideally you should use a wired connection if possible, or a stable wi-fi connection
Course wasn’t closed properly - make sure you follow the instructions to close the module down as advised. If you just close the window or the browser down then your progress will not save.