An update on this issue as I am upgrading again and checking for 'odd behaviour' at each stage.
I can confirm that once upgraded to 2.2.11, the issue with being able to see and add questions etc happens when logged in as Admin and using the 'switch role to.. Student' function.
When logged in using a test Student account, it does NOT give access to the question bank etc.
Whilst this is good to know, it does mean the Switch role to Student (which I used often after making changes to check the view for students) cannot be used as it shows things which are NOT visible when logged in as a student.
I might have thought this a bug, but cannot find anyone else reported the same issue.
I guess I will just have to learn to do without Switch role to... for now.
Onwards!