Specialization Course won't open after due date

Summary:

Every month we have team members that say they can't open a course in a specialization after a due date for the assignment. None have a published end date, nor does the initiative. We also reconcile any changes if needed. We don't use any kind of rule that would limit them to not go past the due date. Is this an unwritten rule for Specializations and/or assignments? Or is there something we are missing?

Content (please ensure you mask any confidential information):

Specializations, Courses.

Version (include the version you are using, if applicable):

Redwood

Code Snippet (add any code snippets that support your topic, if applicable):