We are often required to republish an older course to ensure it is compatible with the latest browsers and to take advantage of better mobile solution.
We have many older courses built in older versions of Studio. If a learner is 1/2 way through a course, and we republish and replace the existing course, when the user clicks on "resume course," the course freezes. (If the learner chooses not to resume, it works fine.)
If we republish as auto-resume, the course immediately freezes.
We are working the Absorb LMS angle, but we all suspect this is Articulate related.
p.s. Note that we have tried a wide variety of courses with the same result. All of our courses are over 100MB so we cannot easily test on SCORMCloud.