Why do deleted groups still show up in Insights? Can I remove them?
A group is displayed in Insights whenever there are tickets associated with that group. This means that it is possible to have deleted groups appear in Insights because, although the group has been deleted, it will still be associated with historical tickets within your Support account. Insights provides you with this feature so you can still collect and report on data of historical tickets such as group. Unfortunately there is no way to delete or remove these groups from your Insights project, regardless of a data re-sync.