To be honest, this reply makes it sound as if they opened the quiz, looked at a few questions, then hit submit so it marks the item complete. From my experience of seeing students do this, if parents/teachers are less familiar with Canvas, the student could:
- Tell their parents they have no missing work (it was submitted so won't show up as missing)
- Tell their parents/teachers they submitted it, but Canvas did not save their answers (rare and tech support might be able to discern if true). The equivalent of "the dog ate my homework."
I've seen similar where students hit the X on the home page "To-Do List" so it clears out something they need to do so if their parents ask if they have any work to finish, it has a message indicating nothing needs to be done.
The log entry should also show how long the student took to complete. Is that time significantly shorter than everyone else? If yes, does this student usually turn things in rushed or do they put in solid work with effort? You mention the student has multiple assignments with 0's earned. If everyone else took an average of 20 minutes to complete the quiz and little Johnny took only 4 minutes, that is a red flag that the student is not being entirely honest with you.
Here might be a solution. Have the student sit down with you and retake it. Apologize profusely, but tech support has asked you to observe this happening. Then also explain that you want to record the answers so that if the glitch occurs again, you have a record of their answers. Get out a printed copy and record their answers as they go. Then they HAVE TO notify you before hitting submit so you can observe and document what happens for tech support. I suspect that the problem will magically resolve itself.