Hi,
I'm surprised that the course opened at all after adding a new Lesson before Lesson 1.
Changing the structure of a course in this way that is already in use, will typically result in a "blank screen" condition for returning students, because the old student suspend data no longer matches the new structure of the course.
As your LMS is not producing the "blank screen" condition for course structural changes, the only way to avoid this is to always add your new Lessons at the bottom of the course structure.
This method of adding content to an existing course is also going to produce issues for students that completed and passed the first version of the course.
They will most likely maintain their LMS completed/passed status even though they haven't attempted the new Lessons.
