When I download a PDF doc from a course, the latest version of that document disappears !

@wonderful_mck It sounds like you're encountering a caching issue rather than a permission issue, particularly since it works correctly on your phone and the problem persists after clearing some cache. Your Mac's Chrome browser is likely holding onto an older version of the document in its cache, even when the website is serving the updated file.

To resolve this, you'll need to clear your Chrome browser's cache and site data specifically for the website hosting your course materials. Go to Chrome's settings, navigate to "Privacy and security," then "Clear Browse data." Select "Cached images and files" and "Cookies and other site data," ensuring the time range is set to "All time" or at least a period that covers when the issue started. After clearing, restart Chrome and try accessing the document again.

If the issue persists, it's also worth trying to open the file in an Incognito window in Chrome (which doesn't use existing cache or cookies) to see if that resolves it, or attempting to use a different browser on your Mac to further isolate if the problem is specific to your Chrome installation or a deeper system-level caching problem. If you've also installed any extensions that interact with PDFs or document viewing, temporarily disabling them might help rule out conflicts.