Searching for a Distribution Group from the "Member Of" tab of a User object shows duplicate results.
After upgrading to ActiveRoles Server 6.9 Generic Patch 4, it is noted that searching for a Distribution Group from the Member Of tab of a User object shows duplicate results. Selecting either of the displayed Distribution Groups adds the User to that Group as expected.
This issue is a product defect which is being tracked as Defect ID TF00667079.
Waiting for fix in a future release of ActiveRoles Server.