We have addressed the problem described in a previous posting so that the automatic child-course groups in multi-section Moodles behave as expected. Many thank to those who reported the issue!
Welcome to Moodle @ Smith College!
It has come to our attention recently that there is a problem with the automatic groups that reflect child course enrollments for multi-section courses with a single merged Moodle. In particular, students who change from one section to another within a course are not being removed from their original group. We expect to have a permanent solution soon.