Resuming Rise Content in LMS

Hello, I built a course that is 23 chapters long and takes several hours to complete in Rise.  We have a handful of student's that are having inaccurate resume capabilities (is that called bookmarking?).  The LMS I used for this course is Topyx. This isn't happening to all of the students, only a few.  Here's what is happening: Student "J" is completing chapters 1-7 and completing the chapter quizzes.  They are using the exit course button to exit and return to the LMS.  When they resume the course it is placing them into chapter 3 and not to where they ended at chapter 7.  The students have restricted navigation must pass quizzes with an 80%. We've gone over browser settings and can't seem to find anything wrong. Do you have any suggestions?