I have the Learning Mastery Gradebook enabled in one of my classes with the new gradebook. I haven't looked at it in several weeks. I'm pretty sure I recall that clicking a column header performed a sort of the data based on that column, either in ascending or descending order. When I checked today, clicking a column header only seems to provide sorting by student last name (asc/descending) NOT by the data -- regardless of which column I click.
I understand from How do I use the Learning Mastery Gradebook to view outcome results in a course from the New Gradebook? that columns can be sorted -- it doesn't go into detail, but clicking the column header is my instinct.
I understand from https://community.canvaslms.com/message/77244-re-sorting-outcomes-in-learning-mastery-gradebook?commentID=77244#comment-… that sorted columns return to a natural order once I leave the class. That's not my problem.