Problem 1) I have used the speedgrader before without problems, but now, although the total score is shown, the score for individual questions is blank and I am receiving a message that the score must be reviewed. The only thing did was to reschedule the test for students be able to do the test in different times.
Problem 2) I have used the option of "multiple choice" before, when it would appear boxes for correct answers and for incorrect. Now I only see boxes for "possible answers". It looks different from before...
Your best bet for issues like this is to put in a Canvas Help ticket to Canvas Support. To do this go to the quiz and then click on the Help icon (bottom left) and Report a Problem.