Interesting Anomaly in Storyline360 Courses

We have several courses (dozens) where, for some users, a page loads with what appears to be another instance of the course embedded in a layer that does not exist on the slide. This second embedded instance of the course becomes the active instance and the original instance becomes disabled. Because only a small portion of the course is visible through the embedded frame, navigation elements are often not accessible and the user's progress is stopped. Often, the slide that loads as this embedded instance is the slide that occurs immediately following the current slide (we have been able to determine this by manipulating the frame's CSS in the browser's developer tool).

These courses were published using Storyline360 v3.38.21861.0 and have since been updated to Storyline360 v3.47.23871.0 to see if the problem would be resolved by a released bug fix. But the problem persists. We have seen this issue occur in both SCORM 2004 and SCORM 1.2 packages across 5 separate LMSs (including SCORM Cloud).

Most users do not experience this issue, but a small percentage of users do. We have collected OS, machine, and browser information for the affected users in an attempt at identifying any common thread amongst the instances and users, but it appears to occur randomly. Although we can log in as the user reporting the problem to verify the issue and gather data, we have been unsuccessful at trying to replicate the problem.

So far, we have only been able to resolve this issue by clearing the user's suspend data and manually progressing through the course to get them back to the slide where they got stuck. However, this is not an ideal long-term solution as these are commercial products sold to thousands of customers.

Has anyone else come across this anomaly? We have an Articulate support ticket open to try and diagnose and resolve the issue, but I'm wondering if anyone else has been affected.