I'd just like to add our vote for Articulate to prioritise this to find a permanent fix within the drivers.
I see that there is a recent update where you can 'reset learner progress' when republishing in the export settings. The info on the Articulate website states:
Note: If you delete a lesson in your course, then update the course in your LMS, some learners might see a blank page. If this happens, select More settings and click the Reset Learner Progress option when you export your course. Then, when learners launch the newly updated course in your LMS, their progress will be reset. Their quiz data will be retained.
This isn't a brilliant fix as completion progress is lost, but at least they can access the lesson.