Separate Groups Grading

I am attempting to use conditional activities in an Assignment so I can have different due dates.

Moodle 2.7.3+

Activity completion is on.

Groups is on.

enablegroupmembersonlyis disabled

Restriction by group under Manage Restrictions is set to show.

However when I attempt to "Add Restriction", only Acitvity completion, Date, Grade, User profile, and Restriction set are showing.  Group is Missing.

What can I do to make sure the Group button is showing is showing under "Add Restriction"

OR

Is there another way of having different due dates by group for an assignment?