Well, I'm pretty sure there is a reasonable explanation, and it would likely have to do with permissions and capabilities.
There are certain capabilities that user must have to see that option. Perhaps capabilities were changed on roles, or users were unassigned / assigned to different roles.
Also, if you are using "public" questionnaires. and looking at an instance of one in a course, the user must have the appropriate capability in the origin course.
There are certain capabilities that user must have to see that option. Perhaps capabilities were changed on roles, or users were unassigned / assigned to different roles.
Also, if you are using "public" questionnaires. and looking at an instance of one in a course, the user must have the appropriate capability in the origin course.