I have used "SpeedGrader" to grade quizzes.  I have clicked the bottom "update" button on each quiz as I finish grading it to update the scores.

And still, despite each quiz having a non-zero score associated with it, the gradebook shows all zeroes.

See attached screenshot. 

Circled on the left: the grade for this particular student's quiz submission, for which I have already clicked "update" at the bottom.

Circled on the right: 0/5, which is what the gradebook continues to reflect.

Is this really the state of Canvas?