I am having the same problem;
Students mark for quiz #5 is not showing up in the grade book. They can see it from the actual quiz activity page but not the grade book.
Quiz setting was set to “Attempts must be submitted before time expires, or they are not counted” I switched it to be “Open attempts are submitted automatically” and regarded students attempt using “Regrade all” method but this did not fix the problem. I backed up the course and did a second attempt to regrade using “Dry run of full regrade” still that did not fix the problem.
Image from Quiz Review Attempt page - Grades are listed
Image from Grade book page - Grades are set to 0.00
Student View page - Grade is listed
Student view Grade book - Grade is not listed (Dropped)
Can someone help please?