We use the API to pull data for a report. When using the listenrollments command for a particular course, a reference GUID is the same for two of the periods. The single digit ID for each period is distinct across the periods in the data returned by the API though, and when we look at the domain level settings, the reference GUIDs for the periods are distinct. So far, we're only seeing this issue for one course, in one school.
Any idea on how this might have occurred, maybe through some action in the UI? And in general, should the GUIDs be safe to use as a way to match up course periods with domain periods?