When enrolled in multiple courses (more or less simultaneously), some of our students are only able to access all the content for the first course they accept the invitation for. They are then denied access to subsequent courses (screenshot attached), or are only able to access some content for those courses, e.g. they can view modules and pages but not quizzes. When I have looked at the information for the student I can see that they are enrolled in all courses and have accepted all the invitiations, there is nothing to indicate that they would not have access to part or all of a course.
We have other students in these courses (who only had one enrolment) that have completed the course in full, so I know that the course and all content within the course has been published.
I enrolled myself as a student to test this and the in first course I accepted an invitation for I could access all content, but the subsequent courses did not alow me access to the quizzes (attached), though I could access evrything else.