If a movement isn't contributing to a movement volume group, it's because that movement has yet to be added to one. You'll know you haven't received any credit if you don't see the Movement Volume section on your workout session screen immediately after logging a new result (below).
Movement volume groups contain various different movements. If you think you aren't getting credit for one when you should be, please contact support@btwb.com and let us know. We'll get the movement added to a group asap.