Using the KISS (keep it simple, silly)), is it an assignable unit (AU on the Home ribbon). Where do you have the AICC_Lesson_Status action set? If it’s on a button that goes to a new page or on the close course button, and sometimes the next/exit happens before the set status is set, even if the set status is the first action. I add the set status as an onPageShow with the hopes it will still set it even if the user closes the course using the X on the window.
I have a similar intermittent problem with my LMS, Pathlore, where sometimes the test score will be recorded, but the completion status is not. The response from my administrator says that it’s typically related to how long the user takes between the time the values are set and closing the course. Thankfully, it’s been intermittent for me and users can go back in, resume and close and the information transfers.