Students submitted their work to an unpublished assignment?

[jpl]

I have an interesting problem.  I created an assignment (Final Exam) in Canvas at the beginning of the year so that students would see it on the calendar.  Just before this due date, I created the actual exam and posted it under a different title.  I thought I had unpublished the original exam, but who knows.    Anyway, it turns out three students were able to submit to the original assignment AND  the assignment is still unpublished.  See picture.

I was under the impression that one could not "unpublish" an assignment once students has submitted work, so something very strange is happening here.

[Steven_S · Accepted solution]

I had a similar problem with a quiz that had passed its until date, and canvas chat support tracked it down to an odd interaction with cached pages.  Those three students may have submitted to a cached page from before you unpublished the dummy assignment.  That shouldn't be possible, so this is something to address to canvas support. 

For the future, you can create a page with a to-do date so that the item is available on student calendars, or if you create an assignment as a placeholder set it to submission type "no submission" or "on paper."  That way there is no option for students to submit through the dummy assignment.

You can also use module rules to control when students have access to dummy assignments, and so make all your changes in the original turning the dummy into an actual assignment before the module unlocks.  It will still be on the students calendar, but it will not let students open it before the module unlocks.