I understand, during the first week of add/drop as students are adding a course, Canvas will not automatically randomly assign them to a group. The system requires the instructor enter and activate the feature again. 

". ,, students are not being automatically added to Student Groups after the 'Randomly Assign Students' button was pressed prior to their enrollment. This is working as intended, newly added students will not be automatically added to the Student Groups as that setting only affects current enrollments for students listed on the left panel and not yet in groups at the time it is pressed. You would need to press this button again if new enrollments are being added to the course."

I would like the system to randomly assign students as they enter the class so they can begin the assignment promptly.