Yes at the moment this is a known limitation for doing courses offline, but it's not one that can be easily fixed. If the contents of a course are restricted, the user doesn't have permissions to see it so the application cannot obtain them from the server to store it offline.
The only suggestion I have is that you think about why a section is restricted. If you're only doing it to enforce the order in which they learn the materials, maybe it isn't as important as allowing them to download the course for offline use. It depends on your use-case .
>>it is a requirement that a student taking online state approved courses, not be able to skip course material. Therefore, the need to restrict activities