Instance and Enrollment issue

Summary

Instance/Assessment working in Preview but then not in the Enrollment for the Course

Content

Has anyone ever come across this?

We set up a class, set up the enrollment to make a course, set up  the assessment and the instance, checked the instance in preview, all was great.

But then when we got to my enrollments and try to take the assessment the instance functionality isn't there.  Instead of taking us into the assessment it just pushes us back to the home page or enrollment search page.

I am having the trouble in both my parent site and my sublearn site - any ideas??