Canvas randomly auto-grading essay questions

cweddle
Community Explorer

I apologize if this has been asked before, but I'm not finding it in a search, possibly because the associated search terms are too general:

I am grading a quiz I gave last week that includes multiple choice and essay questions. I assumed Canvas would leave the grades for the essay questions blank, since I did not provide any information that would allow it to assess students' answers (I mean, how would that even work?). What I am finding is that although it often does leave the grades for those questions blank, and alert me at the top of the quiz to the fact that they need attention, occasionally it will randomly fill in points for those questions on some students' quizzes. Other times, it will fill the point boxes in with "NaN" but apparently counts it as "graded" (so it doesn't list it at the top as needing attention). Both create problems, because in dealing with a large number of students' quizzes, it would be easy for me not to realize that those questions had not actually been graded, and that Canvas had assigned a number that is probably higher or lower than it should be. 

Does anyone know what causes this to happen and how to prevent it? There seems to be no pattern to it (i.e., it happens on different questions on different students' quizzes, doesn't happen at all on most of them, etc.).

Any help much appreciated!