Thank you so much David.
My colleague and I decided to be on the safe side and as the group was small we allocated the peers manually good practice.
As the grading component is not as important (the student only have to complete the activity) will keep a note re the "manually grant the same grade to all group members".
These helpful hints will go a long way to helping us when we re-do the activity again in a few weeks.
And once again thank-you for the quick response it is very much appreciated.