Quick Groups have stopped working

I have been working with DraftSight Free for about a week and have used the right click EntityGroup/Qick Group function successfully. The created group could be then selected by clicking any entity in the group.

However, within the last couple of days this function has become partially disabled. While groups are still created, clicking on an entity in the group only selects that entity, which renders the group unusable for modifications.

I have scoured the Help files and iQuestions for a solution, but haven't found anything. It's entirely possible that I have  inadvertently switched off some parameter in my exploration of the software, but my unfamiliarity makes it difficult to correct the problem.

Thanks in advance for your assistance.

DraftSight 2015 x64

File Version 13.0.0.56311

Product Version 2014.7.495

Windows 7 Home Premium x64 SP1