@DarleneHicks do you have any assignments due in the time frame that is showing for Tasks for Canvas? if the setting is for 3 days, and your tasks are farther out, they won't show? Tell the students to go to options for the extension and select week or month. There is supposedly a rolling option, but it is not working for me(based on what I thinnk it should do). Also, they can change the list length. Just some thoughts.
Just noticed that there is an option for show rings for courses with active assignments. So if that is checked and you have no active assignments, then your course won't show on the rings
Ron