Rise 360 START COURSE button missing

Has anyone come across an issue with the START COURSE button on a Rise course disappearing?  We have a very large course that was created for a customer and we send the link out to them to give access to a lot of people.  When we "preview" it and when they go into it, the START COURSE button is there.  However, every few weeks it's all of a sudden gone and there is only a very small "down arrow".  The solution we've found is to duplicate the course, but we can't continue to do that every few weeks.  Articulate support didn't have a solution after submitting a ticket.  Any suggestions or solutions?