Hidden course quizzes show up in the student gradebook despite settings for them to remain hidden. This seems to only effect quizzes and not other hidden activities. Tim Hunt wonders if this bug is a regression related to https://tracker.moodle.org/browse/MDL-18301. A description of the problem including screenshots can be accessed here https://moodle.org/mod/forum/discuss.php?d=231992#p1010947. Although similar instances have been reported in the past, this seems to be a new bug.