Activity completion for a quiz is configured to require a passing grade. After a quiz attempt is manually graded, if the overall score meets or exceeds the "grade to pass" value, the quiz is still not marked as complete for the student. To get the quiz to be marked as complete, the instructor must open and save the quiz settings (no edits required). Here's a video demonstrating the issue: http://screencast.com/t/ps6mknCrxWM

STEPS TO REPLICATE
1. Create a course with activity completion enabled
2. Enroll one student
3. Create a quiz
4. Under Grade, set the grade to pass as 5 and give students 2 attempts
5. Under Activity Completion, set it to mark as completion when student receives a passing grade
6. Save the quiz settings
7. Edit the quiz and add one essay question worth 10 points
8. Log in as the enrolled student
9. Complete the one quiz
10. Log back in as the instructor and grade the attempt, give the student 10 points
11. Log in as the student and navigate to the course section containing the quiz.

OBSERVED BEHAVIOR:
No completion checkmark is there for this quiz despite passed grade.

EXPECTED BEHAVIOR:
A checkmark displays next to the quiz indicating the activity is complete as the student has received a passing grade.

12. Log in as the instructor again, open the quiz settings and just re-save the page (no changes made)
13. Log in as the student once again and see there's now a checkmark in the completion box

REPLICATION LOCATIONS
Replicated in 2.9.3 and 3.0.4 environments.

ADDITIONAL INVESTIGATION NOTES
1. This issue can also be replicated by manually grading a quiz consisting of only question types that are graded automatically. Create a quiz with the same settings as above but add a 10-point multiple choice question rather than an essay question. When taking the quiz as the student, purposely get the question wrong. As the instructor manually override that incorrect grade with a grade of 7 points. This should trigger the completion checkmark, but again the quiz is not marked complete for the student until the instructor re-saves the settings on the quiz.
2. If there are multiple attempts, only students that have an attempt made before the re-save will see the checkmark. If subsequent student attempts are made and graded, the activity completion settings have to be unlocked and then the quiz settings re-saved again so everyone sees the checkmark.

USER IMPACT
Instructors are unable to reliably use activity completion tracking on quizzes which require manual grading.