Our learning management system (LMS) is a dynamic and complicated software involving lots of back-and-forth information communication between your web browser and the server as you move through your course. At the same time, your browser thinks its job is to load web pages as fast as it can, and one way it does that is to try to cache and hold onto content already downloaded and keep showing that to you rather than download fresh content.

This produces a conflict of purposes; the server wants to download new information, and the browser would prefer to show you the page as it looked the last time you looked at it. The way to solve this is to clear your browser cache files, forcing the browser to download fresh data from the server, including data from your most recent actions in the course. 

Here's a helpful resource on How To Clear Cache for All Major Browsers: https://kinsta.com/knowledgebase/how-to-clear-browser-cache/