I have a number of Canvas quizzes assigned to my students throughout the course of the semester. I set these up with due dates before the semester started and they usually run pretty smoothly (I've done this many times). However, this semester, the quizzes for one course keep losing their due dates. I set the date, everything looks good, and then a few days later the due date will be gone, just completely erased. This seems to happen to random quizzes, although it frequently happens to multiple quizzes at the same time, but not always the same ones.
I'm not sure if this is relevant, but the course is a blueprint child course. I have a blueprint parent course where I make changes, and then I sync the changes to three other courses so that they all look the same. These quizzes are assigned to all three courses, although I set the due dates individually for each one (they have class on different days). At first, I thought the due dates might be getting erased when I synced changes from the parent course. However, the other two courses have had no problem with their due dates. Additionally, the last time I synced a change, I double-checked the quiz due dates to make sure that they were still correct, and everything looked good.
What could be happening? Is there a way to check the history on these due dates to see when they've been changed?