We have a building where after the original master schedule was made, changes were made and some students were moved to different teachers. When that happened, they were listed with two teachers in Canvas and we went in and deleted the students from their old sections, leaving them only in the correct course.
What has been happening is that those students have been popping back into Canvas after we deleted them. We have deleted them several different ways, always with the same result. They pop back in and then the parents of those students get a bunch of notifications of missing work from the teacher the student should no longer be with.
They don't show up as enrolled in the section, but they pop back into the gradebook, and if you do a People search on the student and look a their enrollments, it shows up there with a notation of "Completed, Enrolled as a Student"