There are two reasons you may be taken to the lesson list instead of the lesson itself when selecting a lesson link.
1. You have not yet completed the prerequisite lessons at the beginning of the course.
Courses include prerequisite lessons such as "Getting Started" and "Lab Safety" that will show you how to complete your lessons in SI Cloud. (There may be additional prerequisite lessons depending on the course's discipline and experiments). Until the prerequisites are completed, the rest of the lessons are locked to you and selecting a lesson will automatically take you to your lesson list.
2. If you have completed your prerequisite lessons, there is likely an error in your course's setup.
Contact your instructor so that they may resolve the issue.